Fluorescence imaging assembly using an operating room lighting device

Abstract

Fluorescence imaging assembly using an operating theatre lighting device The fluorescence imaging assembly (10) comprises a fluorescence imaging device (14) capable of detecting fluorescence radiation, and an operating theatre lighting device (12), comprising at least one white light source (18) generating white light comprising in its spectrum a first endogenous fluorescence excitation wavelength. For each white light source (18), at least one first removable filtering element (20) is capable of filtering wavelengths greater than a first predefined value between 675 and 725 nm, preferably equal to 700 nm. The light source forms a first means for generating fluorescence excitation light. Figure for abstract: Figure 1

Description

Title of the invention: Fluorescence imaging assembly using an operating room lighting device

[0001] The present invention relates to a fluorescence imaging assembly, in particular for surgical application.

[0002] In medicine, fluorescence imaging involves exciting a substance at certain wavelengths by a light source, so that the substance emits fluorescence radiation that can be captured by a camera and visualized in real time.

[0003] Certain human tissues intrinsically emit (without added fluorescent marker) fluorescent radiation when excited at certain wavelengths; this is called tissue autofluorescence (also called endogenous fluorescence). The major advantage of autofluorescence imaging is that it is completely non-invasive for the patient (no intravenous or subcutaneous injection of tracer).

[0004] In other cases, a fluorescent marker is injected or ingested, this fluorescent marker being excited to emit fluorescent radiation (this is then called exogenous fluorescence).

[0005] Endogenous fluorescence imaging and exogenous fluorescence imaging can provide complementary information useful for clinical interpretation.

[0006] For example, during a thyroidectomy, the thyroid gland must be removed while preserving the parathyroid glands, which are generally very close to it. Locating the parathyroid glands is often difficult with the naked eye and requires a great deal of experience on the part of the surgeon. The autofluorescence of these glands makes them easier to locate.

[0007] Thus, some surgeons have been able to demonstrate that the number of postoperative complications decreases when the surgeon secures his procedure using autofluorescence imaging.

[0008] However, autofluorescence imaging only provides contextual information, namely a potential location of the parathyroid glands. Indeed, there are generally false positives, due to the fact that there are many substances capable of autofluorescence. Autofluorescence imaging therefore mainly makes it possible to limit the number of areas to be analyzed.

[0009] When dissecting the thyroid, the surgeon also needs functional information: 1) identify the vessels that supply each of these parathyroid glands so as not to damage them and preserve their functionality, 2) check that the parathyroid glands are well vascularized. Indeed, to ensure the viability of the tissues, it is important to preserve the vessels that vascularize them. Imaging Autofluorescence alone does not allow observation of irrigating vessels or tissue perfusion. On the other hand, it is conventional to use the fluorescence of a marker such as indocyanine green (ICG) to visualize the vascular network that supplies the parathyroid glands.

[0010] It should be noted, however, that once the marker is injected, its powerful fluorescence often overwhelms the weaker autofluorescence of the parathyroid gland, so that the autofluorescence can no longer be seen and used to identify the parathyroid glands.

[0011] It should also be noted that other exogenous fluorescence markers can be used. For example, in fluorescence imaging of nerves, there are ALM-488 markers, whose fluorescence is excited between 450 and 520 nm, and emitting between 500 and 600 nm, or ALM-594 markers, whose fluorescence is excited between 500 and 620 nm, and emitting between 600 and 700 nm.

[0012] The invention aims in particular to enable effective visualization of autofluorescence, in a simple and economical manner.

[0013] For this purpose, the invention relates in particular to a fluorescence imaging assembly, comprising:

[0014] - a first means for generating excitation light emitting radiation excitation comprising a first endogenous fluorescence excitation wavelength, and

[0015] - a fluorescence imaging device capable of detecting fluorescent radiation rescence,

[0016] characterized in that the imaging assembly comprises:

[0017] - an operating theatre lighting device, comprising at least one source of white light generating a white light including in its spectrum the first endogenous fluorescence excitation wavelength and,

[0018] - for each white light source, at least one first filtering element removable capable of filtering wavelengths greater than a first predefined value between 675 and 725 nm, preferably equal to 700 nm, the first means for generating excitation light being formed by at least one light source.

[0019] The invention provides in particular for using at least the white light of an operating theatre lighting device to excite an autofluorescent tissue. Thus, the fluorescence imaging assembly comprises at least the operating theatre lighting device, and therefore does not require the imaging device to be provided with an autofluorescence excitation means.

[0020] According to other advantageous aspects of the invention, the imaging assembly comprises one or more of the following characteristics, taken in isolation or according to all of them: technically possible combinations:

[0021] - The fluorescence imaging device comprises: - a first means of bandpass filtration, preferably removable, allowing the visualization of wavelengths between a first lower limit and a first upper limit, the first lower limit being between 700 and 750 nm and the first upper limit being between approximately 750 and 900 nm, preferably between 750 and 810 nm, and - preferably, a second removable bandpass filtration means allowing the visualization of wavelengths between a second lower limit and a second upper limit, the second lower limit being between 750 and 810 nm and the second upper limit being between 775 and 900 nm, preferably between 810 and 900 nm.

[0022] - The imaging assembly comprises a first means for generating a light of enhancement of endogenous fluorescence excitation, for example a laser or a light-emitting diode, emitting excitation radiation having a maximum intensity defined by an excitation wavelength of between 600 and 700 nm, the first means for generating excitation-enhancing light preferably being integrated into the operating theatre lighting device.

[0023] - The white light generated by the white light source includes in its spectrum a second wavelength of exogenous fluorescence excitation.

[0024] - The imaging assembly comprises a second light generating means of strengthening of exogenous fluorescence excitation, for example a laser or a light-emitting diode, generating excitation radiation having a maximum intensity defined by an excitation wavelength between 680 and 850 nm, the fluorescence imaging device comprising a filter blocking the wavelength of the second generation means.

[0025] - The second light generating means is integrated into a chosen device among: the imaging device; the operating room lighting device; or an external device different from the imaging device and the operating room lighting device.

[0026] - The operating theatre lighting device comprises, for each source of white light, at least one second removable filtering element capable of substantially filtering wavelengths greater than a second predefined value, the second predefined value being selected between 680 and 850 nm, for example equal to 750 nm, 775 nm, 785 nm or 808 nm.

[0027] - For each white light source, the first and second filtering elements are carried by a wheel, mobile in rotation to bring the first filtration element, the second filtration element, or at least a third element, opposite the white light source.

[0028] - The wheel is common to several sources of white light, and has as many first filter element and second filter element as white light sources corresponding to this wheel, the wheel being sized to bring the same type of filter element opposite each white light source.

[0029] - The imaging assembly has at least three operating configurations, namely: - a first operating configuration for the detection of endogenous fluorescence, using the white light source of the operating room lighting device as a first means of generating excitation light, each white light source being filtered by the corresponding first filtering element; - a second operating configuration for the detection of exogenous fluorescence, in particular for the detection of ICG fluorescence; and - a third operating configuration for color imaging.

[0030] - In the first configuration, the first means for generating a light of enhancement of endogenous fluorescence excitation is activated.

[0031] - In the first configuration, the fluorescence imaging device is filtered to substantially block wavelengths outside the range between about a first lower bound and a first upper bound, the first lower bound being between about 700 and 750 nm, and the first upper bound being between about 775 nm and 900 nm, particularly between 775 nm and 825 nm.

[0032] - In the second operating configuration, each light source white is filtered by the second corresponding filtration element.

[0033] - In the second configuration, the second light generating means exogenous fluorescence excitation is activated.

[0034] - In the second configuration, the fluorescence imaging device is filtered to block wavelengths greater than a second upper limit between 775 and 900 nm, preferably between 810 and 900 nm.

[0035] - In the third configuration, the white light sources are not sen possibly not filtered, or only filtered using a cold filter to reduce radiant energy.

[0036] - The settings for the first, second and third function configurations operation are automatically implemented in response to the selection of a first, second or third operating mode.

[0037] - The adjustments are implemented by rotating at least one of the wheels carrying the filters.

[0038] - The settings are implemented by turning on or off the first means of management generation of a reinforcing light and / or the second means of generating reinforcing light.

[0039] The invention also relates to a method for detecting endogenous fluorescence, comprising exciting an endogenous fluorescent substance with light at a first endogenous fluorescence excitation wavelength, and detecting the endogenous fluorescence by means of a fluorescence imaging device, characterized in that the excitation of the substance is carried out by means of an operating theater illumination device comprising at least one white light source generating white light whose spectrum includes the first endogenous fluorescence excitation wavelength and, for each white light source, at least one removable first filtering element suitable for filtering wavelengths greater than a first predefined value between 675 and 725 nm, preferably equal to 700 nm.

[0040] The invention finally relates to a use of an operating theatre lighting device for exciting a fluorescent substance, with a view to detecting the endogenous or exogenous fluorescence of this substance by means of a fluorescence imaging device.

[0041] Various aspects and advantages of the invention will be highlighted in the following description, given solely by way of non-limiting example, and made with reference to the drawings in which:

[0042] [Fig-1] [Fig.l] schematically represents an imaging assembly according to a first example of an embodiment of the invention;

[0043] [Fig.2] [Fig.2] schematically represents an imaging assembly according to a second exemplary embodiment of the invention;

[0044] [Fig.3] [Fig.3] schematically represents an operating theatre lighting device equipping an imaging assembly according to a third exemplary embodiment of the invention.

[0045] [Fig. 1] shows an imaging assembly 10 according to a first exemplary embodiment. The imaging assembly 10 is intended to observe an area of ​​interest 11.

[0046] The area of ​​interest 11 comprises, for example, a first substance intrinsically emitting fluorescent radiation (endogenous fluorescence) and a second substance emitting fluorescent radiation following the injection of a fluorescent marker (exogenous fluorescence). The fluorescent marker is, for example, indocyanine green.

[0047] The first substance has a fluorescence emission spectrum with a first maximum intensity at a first emission wavelength (e.g., it is the autofluorescence of parathyroid glands with an intensity maximum in the vicinity of 711 nm). The second has a fluorescence emission spectrum with a second maximum intensity at a second emission wavelength (e.g., it is the fluorescence of indocyanine green with a maximum intensity near 820 nm). The fluorescence spectra of the first and second substances are distinct. The first and second emission wavelengths are distinct. For example, the maximum of the fluorescence spectrum of the second substance has a wavelength greater than the maximum of the fluorescence spectrum of the first substance, for the same excitation wavelength used.

[0048] The imaging assembly 10 comprises an operating room lighting device 12, an imaging device 14 and a display device 16 connected to the imaging device 14. The imaging assembly 10 also comprises computing means 30, comprising one or more computers or servers, configured to perform various operations from the output signal or signals of the imaging device 14.

[0049] According to the first embodiment, shown in [Fig.l], the imaging device 14 is separate from the lighting device 12, and can be manipulated independently of this lighting device 12.

[0050] On the other hand, in the second embodiment, shown in [Fig.2], the imaging device 14 is carried by the lighting device 12, preferably at its center.

[0051] In the third embodiment, shown in [Fig.3], the imaging device is also carried by the lighting device 12. The third embodiment differs from the others by the arrangement of filters, which will be described later.

[0052] However, these three embodiments have a similar operation, such that they will be described together. In the following description, unless otherwise specified, everything that will be described will be common to the three embodiments.

[0053] The imaging device 14 is intended to detect a fluorescence radiation emitted from the region of interest 11. This fluorescence radiation can be an endogenous or exogenous fluorescence radiation.

[0054] In order to enable the emission of the fluorescence radiation, the imaging assembly 10 comprises a first means for generating a first excitation radiation having a first endogenous fluorescence excitation wavelength, and preferably a second means for generating a second excitation radiation having a second exogenous fluorescence excitation wavelength. The second excitation means preferably has a maximum intensity at a wavelength greater than the wavelength corresponding to the maximum intensity of the first excitation means.

[0055] The operating theatre lighting device 12 comprises at least one source of white light 18.

[0056] The invention provides for using at least this white light source 18 to excite endogenous fluorescence, by emitting the first excitation radiation having a maximum intensity defined by the first endogenous fluorescence excitation wavelength. For this purpose, the white light 18 comprises, in its spectrum, said first endogenous fluorescence excitation wavelength. This first endogenous fluorescence excitation wavelength is generally between 600 and 700 nm, preferably between 650 and 700 nm. Thus, the white light source 18 forms said first means for generating the first excitation radiation.

[0057] It should be noted that the measured powers, in the wavelengths considered, of the white light emitted by the lighting device 12 are equivalent to those of the lights emitted by conventional devices. For example, it is possible to compare the illuminations, at the level of the incision, of a device for visualizing parathyroids by autofluorescence (Fluobeam® LX Red) and of an operating room lighting device (Volista™ NIR) in the 600-700nm band. The measurement having been carried out:

[0058] - at 10cm from the excitation light source (recommended working distance of the Fluobeam LX Red), and

[0059] - 1m from the operating theatre lighting device (lighting distance re ordered, the imaging device can be positioned 10cm from the incision).

[0060] The power measured for the LX Red is then 75 W / m2, and the power measured for the Volista NIR is 71.2 W / m2 (for the wavelength band [600-700] nm).

[0061] For each white light source 18, the lighting device 12 comprises at least one first removable filtering element 20, capable of filtering wavelengths greater than approximately a first predefined value between 675 and 725 nm, preferably equal to 700 nm. This first filtering element 20 is movable between an active position, in which it is located opposite the corresponding white light source 18 to filter wavelengths greater than the first predefined value, and a retracted position, in which the first filtering element 20 is kept away from the white light source 18 so as not to filter the white light.

[0062] The first filtration element 20 is placed in the active position when the imaging assembly 10 is in the endogenous fluorescence observation configuration.

[0063] Advantageously, the invention also provides for using the white light source 18 to excite an exogenous fluorescence, by emitting the second excitation radiation having a maximum intensity defined by the second exogenous fluorescence excitation wavelength. For this purpose, the white light 18 comprises, in its spectrum, said second exogenous fluorescence excitation wavelength. This second exogenous fluorescence excitation wavelength is generally between 680 and 850 nm, preferably between 750 and 850 nm. Thus, the white light source 18 also forms said second means for generating the second excitation radiation.

[0064] For each white light source 18, the lighting device 12 comprises at least one second removable filtering element 22 capable of substantially filtering wavelengths greater than a second predefined value, the second predefined value being selected between 680 and 850 nm, preferably between 750 and 850 nm, for example equal to 750 nm, 775 nm, 785 nm or 808 nm.

[0065] Advantageously, the filtering of the second filtration element 22 is higher than the filtering of the first filtration element 20, in order to improve the colorimetric quality of the operating room lighting.

[0066] The second filtering element 22 is movable between an active position, in which it is located opposite the corresponding white light source 18 to filter the wavelengths greater than the second predefined value, and a retracted position, in which the second filtering element 22 is kept away from the white light source 18 so as not to filter the white light.

[0067] The second filtration element 22 is placed in the active position when the imaging assembly 10 is in the exogenous fluorescence observation configuration.

[0068] In the example of the third embodiment, shown in [Fig. 3], the first 20 and second 22 filtering elements are carried by a wheel 24. The wheel 24 is then movable in rotation to bring the first filtering element 20, the second filtering element 22, or preferably at least one third element 26, opposite the white light source 18. Said third element 26 does not include any filter, or alternatively includes a cold filter intended to reduce the energy radiant. Said third element 26 is arranged opposite the white light 18 during use in color imaging. The third element 26 advantageously makes it possible to improve the colorimetry of the white light source 18.

[0069] For example, the wheel 24 is common to several light sources 18, and comprises as many first filtration elements 20, second filtration elements 22 and third elements 26 as there are light sources 18 corresponding to this wheel 24. The wheel 24 is dimensioned to bring the same type of element opposite each light source 18. In [Fig.3], each wheel 24 is shown in a configuration where the second filtration elements 22 are opposite the corresponding light sources 18.

[0070] The imaging device 14 is intended to capture an image of the area of ​​interest 11, and to transcribe this image onto the display device 16.

[0071] The imaging device 14 conventionally comprises a detector 15 provided with an objective comprising at least one optical lens. The imaging device 14 also comprises filtering means 28.

[0072] The filtering means 28 comprise a first bandpass filtering means 32, preferably removable, allowing the visualization of wavelengths between a first lower limit and a first upper limit, the first lower limit preferably being between 700 and 750 nm. This first filtering means 32 therefore blocks wavelengths lower than the endogenous fluorescence wavelengths of interest, for example by blocking the wavelengths of ambient white lighting sources (ceiling light and window), white light sources 18 or excitation lighting.

[0073] Preferably, the first filtering means 32 blocks wavelengths greater than the first upper bound in the endogenous fluorescence imaging configuration, to block or substantially reduce exogenous fluorescence and thus not interfere with the detection of endogenous fluorescence, for example to block the strongest ICG fluorescence during autofluorescence imaging of the parathyroid gland. The first upper bound is between approximately 750 and 900 nm, preferably between 750 and 810 nm.

[0074] Advantageously, a second low-pass type filter is positioned between the first filtration means 32 and the sensor 15 to block wavelengths greater than approximately 750 and 900 nm, preferably between 750 and 810 nm.

[0075] Preferably, the filtering means 28 comprise a second removable bandpass filtering means 34 allowing the visualization of wavelengths between a second lower limit and a second upper limit. The second lower limit is for example between 750 and 810 nm. This second filtering means 34 therefore blocks wavelengths lower than the exogenous fluorescence wavelengths of interest, for example by blocking the wavelengths of ambient white lighting sources (ceiling light and window), white light sources 18 or excitation lighting. The second upper limit is between 775 and 900 nm, preferably between 810 and 900 nm.

[0076] It is noted that both the endogenous fluorescence and exogenous fluorescence wavelengths are wavelength bands, and the lower limit of the endogenous fluorescence wavelengths is, in the described example, lower than the lower limit of the exogenous fluorescence wavelengths.

[0077] It is however possible, as a variant, to provide exogenous fluorescence of a wavelength lower than the endogenous fluorescence. This is particularly the case when using an exogenous marker of the CY5, ALM-488 or ALM-594 type.

[0078] Furthermore, it should be noted that exogenous and endogenous fluorescence may include certain wavelengths of light, usually at low intensities, beyond the selected endogenous and exogenous fluorescence wavelength bands that are detected and used for imaging in this system.

[0079] The filtering means 28 finally comprise a third removable means 36, for the use of the imaging device 14 in color imaging mode.

[0080] This third removable means 36 is for example a filter called IR-CUT. It is a low-pass type filter, which has the effect of blocking wavelengths beyond a limit A, A being chosen in the interval 650-800 nm. Its function is to improve the colorimetric rendering of the color image acquired by the sensor 15.

[0081] In the example of the third embodiment, the first filtration means 32, second filtration means 34 and third means 36 are carried by a wheel, configured to bring one of these means opposite the sensor 15 depending on the desired configuration.

[0082] Advantageously, in order to reinforce the excitation of the endogenous fluorescence, the imaging assembly 10 comprises at least a first means 38 for generating a light for reinforcing the excitation of endogenous fluorescence, emitting an excitation radiation having a maximum intensity defined by a reinforcing excitation wavelength of between 600 and 700 nm. The first generation means 38 is for example a laser source, a light-emitting diode, or a VCSEL source (acronym for "Vertical Cavity Surface Emitting Laser").

[0083] The first excitation enhancing light generating means 38 are generally additional light sources distinct from the white light sources 18, although the white lights 18 may also be used to excite endogenous fluorescence.

[0084] In the third embodiment, the first excitation enhancement light generating means 38 is preferably integrated into the operating room lighting device 12, as shown in [Fig.3].

[0085] Alternatively, the first means 38 for generating excitation enhancement light is carried by an external device distinct from the lighting device 12 and the imaging device 14, as shown in FIGS. 1 and 2. It will be noted that these variants are compatible for the three embodiments, so that the first means 38 for generating excitation enhancement light could be integrated into the operating room lighting device 12 in the first or second embodiment, or an external device could be used in the third embodiment.

[0086] The first means 38 for generating reinforcing light is activated in particular when it is desired to observe the endogenous fluorescence in the area of ​​interest. 11.

[0087] Advantageously, the first reinforcement means 38 participates in improving the colorimetric quality of the operating room lighting, by having its wavelength and optical power suitably chosen. More particularly, due to the first filtering element 20, the colorimetric quality of the operating room lighting is reduced, in particular in the red levels. By adding the reinforcement light 38 in red wavelengths, the effect of the filters on the colorimetric quality is reduced.

[0088] Advantageously, in order to reinforce the excitation of the exogenous fluorescence, the imaging assembly 10 comprises at least one second means 40 for generating a light for reinforcing the excitation of exogenous fluorescence, emitting an excitation radiation having a maximum intensity defined by an excitation wavelength of between 680 and 850 nm. The second generation means 40 is for example a laser source, a light-emitting diode, or a VCSEL source (acronym for "Vertical Cavity Surface Emitting Laser").

[0089] The second means 40 for generating reinforcing light is activated when it is desired to observe the exogenous fluorescence in the area of ​​interest 11.

[0090] Preferably, the imaging device 14 comprises a filter at the wavelength of the second generation means 40, in order to prevent the reflection of this generated light from interfering with the observation of the exogenous fluorescence.

[0091] In the third embodiment, the second excitation enhancement light generating means 40 is preferably integrated into the operating room lighting device 12, as shown in [Fig.3].

[0092] Advantageously, the second reinforcement means 40 contributes to improving the colorimetric quality of the operating room lighting, by having its wavelength and optical power appropriately chosen.

[0093] Alternatively, the second means 40 for generating reinforcing light is integrated into the imaging device 14, or, as shown in FIGS. 1 and 2, integrated into an external device different from the imaging device 14 and the operating room lighting device 12.

[0094] It will be noted that these variants are compatible for the three embodiments, so that the second means 40 for generating excitation reinforcement light could be integrated into the operating theatre lighting device 12 in the first or second embodiment, or an external device could be used in the third embodiment.

[0095] The imaging assembly 10 has at least three operating configurations, namely:

[0096] - a first operating configuration for fluorescence detection endogenous,

[0097] - a second operating configuration for fluorescence detection exogenous; and

[0098] - a third operating configuration for color imaging (i.e. the mode of visualization of tissues in the visible).

[0099] In the first configuration, the white light source 18 is used as a first endogenous fluorescence excitation light source. Each white light source 18 is filtered by the corresponding first filter element 20. For this purpose, each wheel 24 is rotated to bring the first filter elements 20 opposite the corresponding white light sources 18.

[0100] Furthermore, in the first configuration, the fluorescence imaging device 14 is filtered to substantially block wavelengths outside the interval between approximately the first lower limit and 900 nm, and preferably to block wavelengths greater than the first upper limit, which is for example between 750 nm and 810 nm. For this purpose, the first filtration means 32 is arranged in front of the sensor 15 of the imaging device 14, between the sensor 15 and the area of ​​interest 11.

[0101] The first filtration means 32 of the first configuration make it possible to filter the exogenous fluorescence wavelengths (such as those of the ICG) so that they do not reach the sensor 15, so that only the endogenous fluorescence remains predominantly visible. The image then generated in order to be displayed on the display means 16 essentially shows the endogenous fluorescence, in particular of one or more parathyroid glands.

[0102] Preferably, in the first configuration, the first means 38 for generating light for enhancing the endogenous fluorescence excitation is activated.

[0103] Advantageously, all these elements are activated automatically, for example controlled by the calculation means 30.

[0104] In the second configuration, the white light source 18 is advantageously used as a second exogenous fluorescence excitation light source. Each white light source 18 is filtered by the corresponding second filtering element 22. For this purpose, each wheel 24 is rotated to bring the second filtering elements 22 opposite the corresponding white light sources 18.

[0105] Furthermore, in the second configuration, the fluorescence imaging device 14 is filtered to substantially block wavelengths below the second lower limit (between 750 and 810 nm) and above the second upper limit (between 810 and 900 nm). For this purpose, the second filtration means 34 is arranged in front of the sensor 15 of the imaging device 14.

[0106] In the application of ICG and parathyroid autofluorescence, it is not essential to block the parathyroid autofluorescence light during ICG imaging because the ICG fluorescence signal is generally much more intense.

[0107] Preferably, in the second configuration, the second means 40 for generating light for enhancing the excitation of exogenous fluorescence is activated.

[0108] Advantageously, all these elements are activated automatically, for example controlled by the calculation means 30.

[0109] In the third configuration, the white light source 18 is substantially not filtered, or only by a cold filter. For this purpose, the third element 26 is brought opposite the corresponding light source 18.

[0110] It will be recalled here that a cold filter is a light filter that preferentially blocks a red component of white light so that the radiant energy of the white light is reduced with minimal effect on the color temperature or other visible properties of the white light. This may be particularly useful for reducing the heat felt by medical personnel working under strong white light.

[0111] Similarly, the third means 36 is brought opposite the sensor 15 of the imaging device 14.

[0112] Advantageously, all these elements are activated automatically, for example controlled by the calculation means 30. More particularly, in each configuration, the white light filtering elements, the filtering means of the imaging device, and preferably the reinforcing lights, are activated automatically and simultaneously.

[0113] Thus, the settings for the first, second and third operating configurations are preferentially automatically implemented in response to the selection of the first, second or third operating mode.

[0114] Alternatively, these adjustments are made manually.

[0115] In some embodiments, the endogenous fluorescence is excited by the white lights 18 (first operating configuration), and the exogenous fluorescence is further excited by at least the second additional source 40 for generating light for enhancing the exogenous fluorescence excitation, which is preferably activated in the second operating configuration, but not in the first operating configuration. Optionally, the first enhancing light generating means 38 is used to further excite the endogenous fluorescence in the first operating configuration.

[0116] In some housings, the first removable filtering means 32 is configured to prevent light wavelengths below the maximum endogenous fluorescence wavelengths from reaching the sensor 15, and the second means removable filtering means 34 is configured to prevent light wavelengths below the peak exogenous fluorescence wavelengths from reaching the sensor 15. In some embodiments, the first removable filtering means 32 is configured to prevent light wavelengths below the parathyroid gland autofluorescence wavelengths from reaching the sensor 15, and the second removable filtering means 34 is configured to prevent light wavelengths below the peak ICG fluorescence wavelengths from reaching the sensor 15.

[0117] In some embodiments, the autofluorescence wavelengths and the ICG wavelengths are both wavelength bands, and a lower limit of the autofluorescence wavelength band is lower than a lower limit of the ICG wavelength band. The system may detect light in the autofluorescence wavelength band in the first operating configuration, and may detect light in the ICG wavelength band in the second operating configuration, and may preferably create and present respective images in the first and second configurations.

[0118] In some embodiments, the imaging assembly is configured for alternating imaging of parathyroid gland autofluorescence and ICG fluorescence.In particular, the fluorescence imaging device is preferably filtered to significantly block wavelengths above a wavelength A of the sensor 15 when autofluorescence imaging the parathyroid gland to block or significantly reduce ICG fluorescence so that autofluorescence of the parathyroid gland can be detected, the wavelength A preferably being a wavelength between about 750 and 810 nm,

[0119] In some embodiments, in the second operating configuration, the second enhancing light generating means 40 generates excitation light at wavelengths that are normally removed from white light by the first removable filter element in the first operating configuration.For example, in the second operating configuration, the second enhancing light generating means 40 may generate excitation light at wavelengths greater than 700 nm that would be blocked by the first removable filter element in the first operating configuration. This has the advantage of improving the colorimetric quality of the operating room lighting by providing the surgeon with better visibility of the tissues, as well as further improving the exogenous fluorescence, in the second configuration.

[0120] It will be noted that the invention is not limited to the embodiments previously described, but could have various variants without departing from the scope of the claims.

[0121] In particular, the above embodiments have been described for use in exogenous fluorescence using ICG markers. The imaging assembly according to the invention could alternatively be adapted to other markers, such as:

[0122] - ALM-488 (excitation between 450 and 520 nm, emission between 500 and 600 nm); or

[0123] - ALM-594 (excitation in the 500-620 nm band, emission between 600 and 700 nm).

[0124] In this case, each source 18 would be equipped with a removable filtration element adapted to the fluorophore ALM-488 (respectively ALM-594), preferably of the band-pass type, which filters the wavelengths corresponding to the emission band of the ALM-488 (respectively ALM594), and the filtering means 28 comprise a removable filtration means of the band-pass type allowing the wavelengths of the emission band of the ALM-488 (respectively of the ALM-594) to pass.

[0125] In a preferred embodiment, these filtering elements and filtering means are added to those previously described, such that the imaging assembly 10 would further have a fourth operating configuration, called nerve imaging, adapted to the ALM-488 or ALM-594 marker.

[0126] In another embodiment, these filtering elements replace those for ICG fluorescence.

[0127] It will be understood that the invention can be adapted to any type of fluorescence marker, by adequately adapting the filters.

[0128] The number of filters is not limited, such that an imaging assembly 10 can be provided that operates with multiple different fluorescence markers.

Claims

Claims

1. Fluorescence imaging assembly (10), comprising - a first excitation light generating means emitting excitation radiation comprising a first endogenous fluorescence excitation wavelength, and - a fluorescence imaging device (14) capable of detecting fluorescence radiation, characterized in that the imaging assembly (10) comprises: - an operating theater lighting device (12), comprising at least one white light source (18) generating white light comprising in its spectrum the first endogenous fluorescence excitation wavelength and, - for each white light source (18), at least one first removable filtering element (20) capable of filtering wavelengths greater than a first predefined value between 675 and 725 nm, preferably equal to 700 nm, the first excitation light generating means being formed by the at least one light source.

2. Fluorescence imaging assembly (10) according to claim 1, wherein the fluorescence imaging device (14) comprises: - a first bandpass filtering means (32), preferably removable, allowing the visualization of wavelengths between a first lower limit and a first upper limit, the first lower limit being between 700 and 750 nm and the first upper limit being between approximately 750 and 900 nm, preferably between 750 and 810 nm, and - preferably, a second removable bandpass filtering means (34) allowing the visualization of wavelengths between a second lower limit and a second upper limit, the second lower limit being between 750 and 810 nm and the second upper limit being between 775 and 900 nm, preferably between 810 and 900 nm.

3. An imaging assembly (10) according to any preceding claim, comprising a first means (38) for generating endogenous fluorescence excitation enhancing light, for example a laser or a light-emitting diode, emitting excitation radiation having an intensity maximum defined by an excitation wavelength of between 600 and 700 nm, the first means (38) for generating an excitation reinforcement light preferably being integrated into the operating theatre lighting device (12).

4. An imaging assembly (10) according to any preceding claim, wherein the white light generated by the white light source (18) includes in its spectrum a second exogenous fluorescence excitation wavelength.

5. Imaging assembly (10) according to any one of the preceding claims, comprising a second means (40) for generating light for enhancing the excitation of exogenous fluorescence, for example a Laser or a Light-Emitting Diode, generating excitation radiation having an intensity maximum defined by an excitation wavelength between 680 and 850 nm, the fluorescence imaging device (14) comprising a filter blocking the wavelength of the second generation means.

6. Imaging assembly (10) according to claim 5, wherein the second light generating means (40) is integrated in a device chosen from: - the imaging device (14); - the operating theatre lighting device (12); or - an external device different from the imaging device (14) and the operating theatre lighting device (12).

7. Imaging assembly (10) according to any one of the preceding claims, in which the operating theatre lighting device (12) comprises, for each white light source (18), at least one second removable filtering element (22) capable of substantially filtering wavelengths greater than a second predefined value, the second predefined value being selected between 680 and 850 nm, for example equal to 750 nm, 775 nm, 785 nm or 808 nm.

8. Imaging assembly (10) according to claim 7, wherein, for each white light source (18), the first (20) and the second (22) filtration element are carried by a wheel (24), movable in rotation to bring the first filtration element (20), the second filtration element (22), or at least one third element (26), opposite the white light source (18).

9. An imaging assembly (10) according to claim 8, wherein the wheel (24) is common to several white light sources (18), and comprises as many first filtration elements (20) and second filtration elements (22) as there are white light sources (18) corresponding to this wheel (24), the wheel (24) being sized to bring the same type of filtration element opposite each white light source (18).

10. An imaging assembly (10) according to any preceding claim, having at least three operating configurations, namely: - a first operating configuration for the detection of endogenous fluorescence, using the white light source (18) of the operating room lighting device (12) as a first excitation light generating means, each white light source (18) being filtered by the corresponding first filter element (20); - a second operating configuration for the detection of exogenous fluorescence, in particular for the detection of ICG fluorescence; and - a third operating configuration for color imaging.

11. An imaging assembly (10) according to claim 10, taken in combination with claim 3, wherein, in the first configuration, the first means (38) for generating endogenous fluorescence excitation enhancing light is activated.

12. The imaging assembly of claim 10 or 11, wherein, in the first configuration, the fluorescence imaging device (14) is filtered to substantially block wavelengths outside the range between about a first lower bound and a first upper bound, the first lower bound being between about 700 and 750 nm, and the first upper bound being between about 775 nm and 900 nm, particularly between 775 nm and 825 nm.

13. An imaging assembly (10) according to one of claims 10 to 12, taken in combination with any one of claims 7 to 9, wherein, in the second operating configuration, each white light source (18) is filtered by the corresponding second filtering element (22).

14. An imaging assembly (10) according to any one of claims 10 to 13, taken in combination with claim 5, wherein, in the second configuration, the second means (40) for generating exogenous fluorescence excitation light is activated.

15. The imaging assembly (10) of claim 13 or 14, wherein in the second configuration the fluorescence imaging device (14) is filtered to block wavelengths greater than a second upper bound between 775 and 900 nm, preferably between 810 and 900 nm.

16. An imaging assembly (10) according to any one of claims 10 to 15, wherein, in the third configuration, the white light sources are substantially unfiltered, or only filtered using a cold filter to reduce radiant energy.

17. An imaging assembly (10) according to any one of claims 10 to 16, wherein the settings for the first, second and third operating configurations are automatically implemented in response to the selection of a first, second or third operating mode.

18. An imaging assembly (10) according to claim 17 taken in combination with claim 7 or 8, wherein the adjustments are implemented by rotating at least one of the wheels (24) carrying the filters.

19. An imaging assembly (10) according to claim 17 or 18, taken in combination with claims 4 and 5, wherein the adjustments are implemented by switching on or off the first means (38) for generating an enhancing light and / or the second means (40) for generating enhancing light.

20. A method for detecting endogenous fluorescence, comprising exciting an endogenously fluorescent substance with light at a first endogenous fluorescence excitation wavelength, and detecting the endogenous fluorescence by means of a fluorescence imaging device (14), characterized in that the excitation of the substance is carried out by means of an operating room lighting device (12), comprising at least one white light source (18) generating a white light comprising in its spectrum the first endogenous fluorescence excitation wavelength and, for each white light source (18), at least one first removable filter element (20) capable of filtering wavelengths greater than a first predefined value between 675 and 725 nm, preferably equal to 700 nm.

21. Use of an operating theatre lighting device (12) for exciting a fluorescent substance, for the purpose of detecting the fluo- endogenous or exogenous fluorescence of this substance by means of a fluorescence imaging device (14).

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