Illumination device for photodynamic therapy, method for treating a skin disease and method for operating an illumination device

Abstract

An Illumination device (100) for photodynamic therapy is provided, the illumination device comprising at least one electromagnetic radiation emitting unit (10), the at least one electromagnetic radiation emitting unit comprising at least one electromagnetic radiation source (1), the electromagnetic radiation source being configured to generate radiation for the irradiation of a region of an irradiation object in an illumination session, wherein the irradiation object is to be arranged at a predetermined object location (300), wherein the predetermined object location is arranged at a distance relative to a radiation output area (11) of the radiation emitting unit through which the radiation generated by the at least one electromagnetic radiation source exits the radiation emitting unit during operation of the illumination device (100).

Claims

1. Illumination device for photodynamic therapy, the illumination device comprising five or more electromagnetic radiation emitting units, each electromagnetic radiation emitting unit comprising several radiation sources, the electromagnetic radiation sources being configured to generate radiation for the irradiation of a region of an irradiation object in an illumination session, wherein the irradiation object is to be arranged at a predetermined object location, wherein the predetermined object location is arranged at a distance relative to radiation output areas of the radiation emitting units through which the radiation generated by the electromagnetic radiation sources exits the respective radiation emitting unit during operation of the illumination device), wherein in each radiation emitting unit a plurality of radiation sources is arranged on a radiation source carrier, the radiation sources on the radiation source carrier are grouped into a plurality of groups, wherein the radiation sources of each group are arranged in a regular, two-dimensional group pattern, wherein at least two groups of the plurality of groups have different group patterns, each group comprises a plurality of radiation sources, a first group with a first group pattern is arranged between a second and a third group, when seen in plan view of the radiation source, the second and the third group have the same group pattern and the first group has a different group pattern, the first group has a lower occupancy density with radiation sources than the second and third groups, wherein the illumination device comprises a distance monitoring system, wherein the distance monitoring system is configured to monitor the distance of the irradiation object from the radiation emitting units, wherein the distance monitoring system comprises a plurality of distance sensors and each radiation emitting unit is assigned a distance sensor for measuring a distance between the irradiation object and the respective radiation emitting unit wherein the illumination device is configured such that each radiation emitting unit, is operable in a low-intensity mode when the distance of the radiation emitting unit to the irradiation object lies within an irradiation range of ±2.0 cm around a nominal distance of 12.0 cm or 12.5 cm, the low-intensity mode being a mode in which the radiation intensity emitted by the radiation emitting unit is at most 50% of a nominal radiation intensity used during the illumination session, wherein the nominal radiation intensity is the radiation intensity which results in the maximum irradiance of the irradiation object during the illumination session, is automatically switched from the low-intensity mode into a no-intensity mode when the distance of the radiation emitting unit to the irradiation object leaves the irradiation range, the no-intensity mode being a mode in which the radiation emitting unit does not emit radiation, is switchable from the low-intensity mode into a nominal-intensity mode, the nominal-intensity mode being a mode in which the radiation intensity is the nominal radiation intensity.

2. Illumination device according to claim 1, wherein an occupancy density of the radiation source carrier with radiation sources is smaller in a center region of the radiation source carrier than in peripheral regions of the radiation source carrier outside the center region.

3. Illumination device according to claim 2, wherein the electromagnetic radiation emitting units are configured to be arranged in a C-shape configuration and/or semi-circle configuration.

4. Illumination device according to claim 3, wherein the radiation source carrier is an elongate carrier with a main direction of extension defining a longitudinal direction (L).

5. Illumination device according to claim 3, wherein, when the distance of the radiation emitting units to the irradiation object is each the nominal distance, the illuminated area on the irradiation object illuminated by the radiation emitting units is at most 32 cm×26 cm and at least 26 cm×20 cm.

6. Illumination device according to claim 5, wherein, in each radiation emitting unit, the pattern of the radiation sources on the radiation source carrier is symmetrical relative to one axis or two axis, which are perpendicular.

7. Illumination device according to claim 6, wherein the occupancy density with radiation sources in the second and third group is at least 1.2 times and at most 5 times the occupancy density in the first group.

8. Illumination device according to claim 7, wherein the radiation emitting unit comprises a unit housing which defines an outer edge of the radiation emitting unit.

9. Illumination device according to claim 8, wherein, in at least one radiation emitting unit, an area on the radiation source carrier occupied with radiation sources is at most 28 cm×16 cm and at least 22 cm×10 cm.

10. Illumination device according to claim 9, wherein the radiation emitting unit comprises one continuous radiation source carrier common for all radiation sources of the radiation emitting unit.

11. Illumination device according to claim 10, wherein the radiation sources are optoelectronic components, wherein the emission spectrum of the optoelectronic components has a peak wavelength in the following range: 635 nm±5 nm.

12. Illumination device according to claim 11, wherein the radiation emitting units are movably connected to one another.

13. Illumination device according to claim 12, wherein in at least one radiation emitting unit, the distance sensor is located offset of a geometric center of the radiation source carrier when viewed in plan view.

14. Illumination device according to claim 13, wherein the distance monitoring system is configured to call for an adjustment of the operation of the illumination device by: varying the distance between the respective radiation emitting unit and the irradiation object.

15. A method for treating a skin disease comprising the following steps: a) applying a pharmaceutical substance to the surface of the skin in a region which is to be treated; b) arranging the skin region to be treated in a predetermined object location of the illumination device according to claim 1, c) irradiating the skin region to be treated with the illumination device.

16. Method according to claim 15, comprising an execution of a start sequence prior to an illumination session, wherein the execution of the start sequence comprises: switching on the radiation emitting units such that the respectively assigned distance sensor is activated for measuring the distance to the irradiation object, adjusting the distance of each radiation emitting unit to the irradiation object until the respective distance is within the irradiation range, when the distance of the respective radiation emitting unit is in the irradiation range, operating the radiation emitting units in the low-intensity mode in order to illuminate the irradiation object with a low radiation intensity, adjusting the position of the irradiation object relative to the illumination device while maintaining the distance of each radiation emitting unit to the irradiation object in the irradiation range, switching a radiation emitting unit from the low-intensity mode into the no-intensity mode if the distance of said radiation emitting unit to the irradiation object leaves the irradiation range, switching at least one radiation emitting unit into the nominal-intensity mode when the position of the irradiation object relative to the illumination device has been adjusted.

17. A method for operating an illumination device according to claim 1, comprising the steps of: providing a measurement signal which is indicative for a distance between at least one radiation emitting unit and the radiation object, generating an operation signal as a function of the measurement signal, said operation signal being configured to trigger a call for an adjustment of the operation of the illumination device.

18. Computer program product comprising machine-readable instructions, which, when loaded and executed on a processor, are configured to cause the illumination device to execute the method of claim 17.

19. A computer-readable medium having stored thereon the computer program product according to claim 18.

20. Illumination device for photodynamic therapy, the illumination device comprising five or more electromagnetic radiation emitting units, each electromagnetic radiation emitting unit comprising several radiation sources, the electromagnetic radiation sources being configured to generate radiation for the irradiation of a region of an irradiation object in an illumination session, wherein the irradiation object is to be arranged at a predetermined object location, wherein the predetermined object location is arranged at a distance relative to radiation output areas of the radiation emitting units through which the radiation generated by the electromagnetic radiation sources exits the respective radiation emitting unit during operation of the illumination device, wherein the illumination device comprises a distance monitoring system, wherein the distance monitoring system is configured to monitor the location and/or the distance of the irradiation object from the radiation emitting units, wherein the distance monitoring system comprises a plurality of distance sensors and each radiation emitting unit is assigned a distance sensor for measuring a distance between the irradiation object and the respective radiation emitting unit, wherein the distance monitoring system is configured to call for an adjustment of the operation of the illumination device by varying the distance between the radiation emitting units and the irradiation object, wherein the illumination device is configured such that each radiation emitting unit, is operable in a low-intensity mode when the distance of the radiation emitting unit to the irradiation object lies within an irradiation range of ±2.0 cm around a nominal distance of 12.0 cm or 12.5 cm, the low-intensity mode being a mode in which the radiation intensity emitted by the radiation emitting unit is at most 50% of a nominal radiation intensity used during the illumination session, wherein the nominal radiation intensity is the radiation intensity which results in the maximum irradiance of the irradiation object during the illumination session, is automatically switched from the low-intensity mode into a no-intensity mode when the distance of the radiation emitting unit to the irradiation object leaves the irradiation range, the no-intensity mode being a mode in which the radiation emitting unit does not emit radiation, is switchable from the low-intensity mode into a nominal-intensity mode, the nominal-intensity mode being a mode in which the radiation intensity is the nominal radiation intensity, wherein in each radiation emitting unit a plurality of radiation sources is arranged on a radiation source carrier, the assigned distance sensor is located offset of a geometric center of the radiation source carrier when viewed in plan view.

Description

BRIEF DESCRIPTION OF THE FIGURES

(1) FIGS. 1 and 2 show an exemplary embodiment of the illumination device in different configurations,

(2) FIGS. 3 to 8 show exemplary embodiments of radiation emitting units,

(3) FIG. 9 shows simulation results for the irradiance on a cylindrical surface obtained with an exemplary embodiment of the illumination device,

(4) FIG. 10 shows an exemplary embodiment of a radiation source,

(5) FIG. 11 shows an exemplary embodiment of the method for treating a skin disease on the basis of a flow chart,

(6) FIG. 12 shows an exemplary embodiment of a graphical user interface of a feedback system.

DETAILED DESCRIPTION OF THE INVENTION

(7) FIG. 1 shows an exemplary embodiment of the illumination device 100 for photodynamic therapy. The illumination device 100 comprises several radiation emitting units 10 which are linearly connected to each other. The radiation emitting units 10 are movably, especially pivotally, connected to each other. For this purpose, hinges 15 are used between the radiation emitting units 10. The radiation emitting units 10 each comprise a radiation output area 11 through which radiation generated by the respective radiation emitting unit 10 is coupled out of the illumination device 100. The output areas 11 are, for example, in each case formed by a (plexiglass or glass) cover plate of the respective radiation emitting unit 10.

(8) In FIG. 1, the illumination device 100 is configured to irradiate a plane surface. The radiation emitting units 10 are arranged such that the radiation output areas 11 lie substantially in a common plane. Main radiation directions of the radiation emitting units 10 are substantially parallel to each other.

(9) FIG. 2 shows the illumination device 100 of FIG. 1 in a different configuration in which the illumination device 100 is configured to irradiate a surface of non-plane shape, namely a cylinder surface, particularly a human face. The radiation emitting units 10 are arranged in a C-shape configuration. For this purpose, the radiation emitting units 10 have been pivoted relative to each other so that the distances of the radiation output areas 11 of the radiation emitting units 10 to the cylinder surface are substantially the same. The rearrangement or movement of the radiation emitting units 10 can be done manually. In the present case, each radiation emitting unit 10 is assigned a motor 42, which is configured to move/pivot the respective radiation emitting unit 10 relative to the further radiation emitting units 10.

(10) The cylinder around which the radiation emitting units 10 are arranged defines a predetermined object location 300. The object location 300 is arranged at a distance to the radiation output areas 11 of the radiation emitting units 10. Inside the object location 300, an irradiation object 200 is arranged. The irradiation object 200 is, for example, a human head. The head 200 is therapeutically treated by irradiating with the irradiation device 100.

(11) During therapeutic treatment, the distances of the radiation emitting units 10 with respect to the irradiation object 200 or with respect to the predetermined object location 300 shall be kept substantially constant, particularly at a nominal distance or within an irradiation range around the nominal distance. For this purpose, the illumination device 100 comprises a location or distance monitoring system 4. The monitoring system 4 comprises distance sensors 40 (see for example FIG. 4), each radiation emitting unit 10 assigned one distance sensor 40. The distance of the radiation emitting units 10 with respect to the irradiation object 200 or the predetermined object location 300 is measured with help of the distance sensors 40.

(12) The monitoring system 4 further comprises an electronic control unit 41 and the motors 42 specified above. During operation of the illumination device 100, the distances of the radiation emitting units 10 to the irradiation object 200 or the predetermined object location 300 is constantly or repeatedly measured with help of the distance sensors 40. Corresponding measurement signals are processed in the monitoring system 4. In case the measurement signals indicate a variation in the distance of one radiation emitting unit 10 to the object 200 or the location 300, a corresponding operation signal or corresponding operations signals are generated, which cause the electronic control unit 41 to operate one or more motors 42 in order to adjust the distance of the radiation emitting units 10 with respect to the irradiation object 200 or the predetermined object location 300. For example, the distance is kept between 50 mm inclusive and 200 mm inclusive, preferably 125 mm. By way of example, if a variation in the distance of more than or equal to 15 mm is measured, the distance is adjusted. For operation the illumination device as stated above and in the following, the computer program product specified herein may be executed on a processor of the illumination device.

(13) Additionally or alternatively, the monitoring system 4 may be configured to call for an adjustment, if the measurement signals form the distance sensors 40 indicate a variation in the distance and/or a leaving of the irradiation range. The operation signal(s) are then configured to call or to trigger a call for such an adjustment. An operator may then move the radiation emitting units 10 manually or by operating the motors 42.

(14) The illumination device 100 may be further configured to adjust the radiation power emitted by the respective radiation emitting unit and/or to adjust the duration of the illumination session. The electronic control unit 41 or a different electronic control unit may then, as a function of the measurement signals of the distance sensors 40, vary the radiation power on the basis of one or more operation signals generated as a function of the measurement signals. For example, if the distance increases, the radiation power is increased. If the distance is reduced, the radiation power may be reduced. Additionally or alternatively, if the distance increases, the duration of the illumination session may be increased and if the distance decreases, the duration of the illumination session may be reduced. Increasing or reducing the duration of the illumination session may be controlled automatically by the monitoring system 4. Particularly, the monitoring system 4 ensures that the predetermined light dose, of e.g. 37 J/cm.sup.2, is received.

(15) It is also possible that, as a function of the measurement signals of the distance sensors 40, the monitoring system 4 may call for an adjustment of the radiation power or the duration of the illumination session, e.g. by an according output on a display or a different user interface of the system (see FIG. 12, for example). An operator may then vary the radiation power of the respective radiation emitting unit 10 or may increase or reduce the duration of the illumination session.

(16) The illumination device 100 may further comprise a feedback system (see FIG. 12) which is configured to provide feedback in order to assist in keeping the irradiation object 200 at the predetermined object location 300. The feedback system may be configured to issue visual, audible and/or tactile feedback which indicates whether the object 200 is at the predetermined object location 300 or at a distance to the radiation emitting units 10 within the irradiation range, respectively, or if an adjustment is required. For this purpose, the feedback system may comprise a display and/or a loudspeaker.

(17) FIG. 12 shows an exemplary embodiment of a graphical user interface 45 of such a feedback system. The user interface 45 illustrates the five radiation emitting units 10a . . . 10e. Three of the radiation emitting units 10a, 10b, 10e are indicated to be not activated/switched on, which is indicated by the “off”-symbols in the respective radiation emitting unit. One radiation emitting unit 10c is activated/switched on and at the correct distance (within the irradiation range), indicated by the check mark in that radiation emitting unit. One radiation emitting unit 10d is activated/switched on but an adjustment of the distance is called for or is being carried out by the monitoring system itself. This is indicated by the two arrows pointing in opposite directions. The representation on the user interface 45 might be generated by the computer program product specified herein.

(18) Before starting an illumination session with the illumination device 100, a start sequence may be performed. Firstly, the operator may switch on each of the radiation emitting units, e.g. by operating one or more buttons on the user interface 45. By switching on, the distance sensors 40 may be activated. After switching on, the radiation emitting units 10 may first be in a no-intensity mode, in which no radiation is emitted, or may be in a low-intensity mode, in which a low radiation intensity is emitted. The operator may then adjust the distances between the radiation emitting units 10 and the irradiation object 200 in order to have the distance of each radiation emitting unit 10 to the irradiation object 200 in the irradiation range, which is, e.g., between 11 cm and 14 cm. The user interface 45 might indicate for each radiation emitting unit 10 the distance to the irradiation object 200 and/or if the distance has to be increased or reduced in order to come into the irradiation range.

(19) As soon as the distance of a radiation emitting unit 10 to the irradiation object 200 is within the irradiation range, a check mark may appear on the user interface 45 for the respective radiation emitting unit 10 (see FIG. 12). The radiation emitting unit 10 in the correct distance, namely in the irradiation range, may then be automatically switched from the no-intensity mode into the low-intensity mode. A corresponding illumination caused by said radiation emitting unit may be visible on the irradiation object 200.

(20) When all radiation emitting units 10 are in the correct distance to the irradiation object 200, particularly when check marks appear on the interface 45 for all radiation emitting units 10, all radiation emitting units 10 may be in the low-intensity mode. The operator may now further adjust the position of the illumination device 100 relative to the irradiation object 200, for example by shifting the illumination device 100 from a position illuminating an upper head region into a position in which the illumination device 100 illuminates the lower head region. During this adjustment of the position, the distances shall be maintained within the irradiation ranges. If, however, during said adjustment of the position the distance of one of the radiation emitting unit 10 leaves the irradiation range, this radiation emitting unit 10 may be automatically switched from the low-intensity mode into the no-intensity mode. The operator may notice this by a change of the illumination on the irradiation object 200. Additionally or alternatively, the interface 45 may indicate this event by letting the checkmark disappear and/or by creating a noise, for example a warning noise. The operator may then readjust the distance of this radiation emitting unit 10.

(21) After the illumination device 100 has been brought into the correct position relative to the irradiation object 200 and when the distances of all radiation emitting units 10 are still in the irradiation range, the operator may switch one or more or all of the radiation emitting units 10 into the nominal-intensity mode, in which the radiation emitting units 10 emit the nominal radiation intensity for the treatment of the skin disease. For example, if the distance of one of the radiation emitting units 10 is not within the irradiation range, only this radiation emitting unit 10 may not be switchable into the nominal-intensity mode. It is also possible that, if at least one of the radiation emitting units 10 is not within the irradiation range, none of the radiation emitting units 10 can be switched into the nominal intensity mode. Alternatively, all radiation emitting units may be switchable into the nominal-intensity mode, regardless whether one or more or all radiation emitting units are within the irradiation range or not. Switching into the nominal-intensity mode may be done manually by the operator, e.g. by operating a start button on the interface.

(22) FIG. 3 shows an exemplary embodiment of a radiation emitting unit 10 in plan view of the radiation emitting unit 10, for example in plan view of the cover plate. The radiation emitting unit 10 of FIG. 3 is, for example, used for all radiation emitting units 10 in the illumination device 100 of FIGS. 1 and 2.

(23) The radiation emitting unit 10 comprises a unit housing 3, for example comprising metal and/or plastic, and a radiation source carrier 2 laterally surrounded by the unit housing 3 in the shown plan view. The unit housing 3 defines a lateral edge 30 of the radiation emitting unit 10 delimiting the radiation emitting unit 10 in a transversal direction T.

(24) The radiation source carrier 2 is, for example, a printed circuit board, PCB for short. The radiation source carrier 2 is an elongated, rectangular shaped carrier. A main direction of extension of the radiation source carrier 2 defines a longitudinal direction L. A direction perpendicular to the longitudinal direction L and running parallel to a main extension plane of the radiation source carrier 2 defines the transversal direction T. The radiation source carrier 2 is delimited in the longitudinal direction L and in the transverse direction T by carrier edges 20.

(25) A plurality of radiation sources 1 is arranged on the radiation source carrier 2. The exact positions of the radiation sources 1 on the radiation source carrier 2 is indicted by the intersection points of the squared brackets. For example, a center of a chip surface of a semiconductor chip assigned to the radiation source overlaps with the respective intersection point.

(26) In the exemplary embodiment, all radiation sources 1 of the radiation emitting unit 10 are arranged on a common radiation source carrier 2. During intended operation, all radiation sources 1 preferably emit radiation in the visible spectrum and of essentially the same color and/or with essentially the same peak wavelength.

(27) As can be seen in FIG. 3, the radiation sources 1 are arranged on the carrier 2 in three different groups 12, 13, 14, wherein each radiation source 1 is uniquely assigned to one group 12, 13, 14. The groups 12, 13, 14 are indicated by the dashed rectangles. A first group 12 with 15 radiation sources 1 is located in a center region of the radiation source carrier 2. A second 13 and a third 14 group, each with 15 radiation sources 1, are located on peripheral regions of the radiation source carrier 2. When viewed along the longitudinal direction L, the second 13 and third 14 group are located before and behind the first group 12. Within each group 12, 13, 14 the radiation sources 1 are arranged in a two-dimension regular group pattern. The group patterns of the second 13 and third 14 group are identical, whereas the group pattern of the first group 12 is different.

(28) In the second 13 and the third 14 group, the radiation sources 1 are arranged more densely on the radiation source carrier 2 than in the first group 12. Thus, the occupancy density of the radiation source carrier 2 with radiation sources 1 in the second 13 and third 14 group is greater than in the first group 12. This arrangement is particular advantageous in terms of a homogeneous irradiation of the irradiation object along the longitudinal direction L.

(29) As can also be seen in FIG. 3, the distance between two adjacent groups 12, 13, 14 is greater than a distance between the radiation sources 1 within a group 12, 13, 14 (the distance between two adjacent groups is the shortest distance between two radiation sources 1 of these two groups). Moreover, it is visible form FIG. 3 that the two-dimensional pattern in which the radiation sources 1 are arranged on the radiation source carrier 2 is symmetric with respect to an axis running parallel to the longitudinal direction L and also with respect to an axis running parallel to the transversal direction T.

(30) In the exemplary embodiment of FIG. 3, a radiation source 1 is arranged in the geometric center of the radiation source carrier 2. Slightly offset from this geometric center, a distance sensor 40 is arrange on the radiation source carrier 2. The distance sensor 40 is part of the previously described monitoring system 4. The distance sensor 40 is, for example, a time-of-flight sensor comprising a laser diode. A distance to the adjacent radiation source 1 in the geometric center is, e.g., 10 mm.

(31) Additionally or alternatively, the distance sensor 40 may be slightly offset, e.g. by at least 5 mm and at most 40 mm, form the center of a radiation field created by the radiation sources of the radiation emitting unit. The center of the radiation field may be the position of the center of mass when integrating over all the radiation sources of the radiation emitting unit.

(32) FIG. 4 shows an exemplary embodiment of a radiation emitting unit 10 in a true-to-scale view. This exemplary embodiment might be used in the illumination device 100 of FIGS. 1 and 2. The transversal distance between two radiation sources 1 being adjacent along the transversal direction T is 30 mm in each case. The longitudinal distance between two radiation sources 1 being adjacent along the longitudinal direction L is 15 mm in the second 13 and third 14 group and is 40 mm in the first group 12. The longitudinal distance between two adjacent groups is 60 mm. The radiation source carrier 2 may have an expansion along the transversal direction T of 160 mm and along the longitudinal direction of 280 mm. Connectors 43, 44 for a connection to other radiation emitting units are provided.

(33) FIG. 5 shows a further exemplary embodiment of a radiation emitting unit 10 in plan view. Also this radiation emitting unit 10 might be used for the radiation emitting units 10 in the illumination device 100 of FIGS. 1 and 2. In contrast to FIGS. 3 and 4, the radiation emitting unit 10 of FIG. 5 does not only comprise one radiation source carrier 2 common to all radiation sources 1 of the respective radiation emitting unit 10, but several radiation source carriers 2. Each radiation source carrier 2 is elongated with a main direction of extension parallel to the longitudinal direction L. Along the transversal direction T running perpendicularly to the main longitudinal direction L, the radiation source carriers 2 are arranged one behind the other.

(34) On each radiation source carrier 2, a plurality of radiation sources 1 is arranged. The radiation sources 1 are in each case arranged in a one-dimensional irregular pattern. Again, on each radiation source carrier 2, the radiation sources 1 are grouped in three groups 12, 13, 14. Each group 12, 13, 14 comprises three radiation sources 1. The first group 12, located in each case between the second 13 and the third 14 group, has a smaller occupancy density with radiation sources 1 than the respective second 13 and third 14 group. The group pattern in each group 12, 13, 14 is regular.

(35) Using several radiation source carriers 2 can be advantageous for further improving the homogeneity of the irradiation pattern. As shown in FIG. 6, which is a cross sectional view along the transversal direction T of FIG. 5, the individual radiation source carriers 2 are arranged angled relative to one another. Consequently, the main radiation directions V of the radiation sources 1 of different radiation source carriers 2 are tilted relative to each other. In the exemplary embodiment of FIG. 6, the radiation source carrier 2 closets to the outer edges 30 of the housing unit 3 is oriented such that the main radiation direction V of the respective radiation sources 1 on this radiation source carrier 2 is outwardly offset from a main radiation direction V of the radiation sources 1 on another radiation source carrier 2 further away from the outer edge 30. In this way irradiation at the outer edges 30 of the radiation emitting unit 10 where the hinges 15 are placed (see FIGS. 1 and 2) can be improved.

(36) The individual radiation source carriers 2 of the radiation emitting unit 10 may be fixed in their relative position to one another. Alternatively, they may be movable relative to another, for example manually or with help of actuators.

(37) FIG. 7 shows a further exemplary embodiment of a radiation emitting unit 10 in plan view. This exemplary embodiment is similar to the ones of FIGS. 3 and 4. Again, all radiation sources 1 are placed on a common radiation source carrier 2. Also this radiation emitting unit 10 may be used for the radiation emitting units 10 in the illumination device 100 of FIGS. 1 and 2.

(38) A difference of FIG. 7 to FIGS. 3 and 4 is the arrangement of the radiation sources 1 on the radiation source carrier 2. In FIG. 7, the first group 12 comprises 25 radiation sources 1 arranged in a regular group pattern. The second 13 and third 14 group each comprise only ten radiation sources 1 in each case arranged in a regular group pattern. In the first group 12, the transversal distances between adjacent radiation sources 1 is in each case 30 mm and the longitudinal distance between adjacent radiation sources 1 is in each case 35 mm. In the second 13 and third 14 group, the transversal distance between adjacent radiation sources 1 is in each case 30 mm and the longitudinal distance is in each case 15 mm. The longitudinal distance between two adjacent groups 12, 13, 14 is 45 mm in each case.

(39) FIG. 8 shows an exemplary embodiment of a radiation emitting unit 10, for which a particularly homogeneous irradiation pattern along the longitudinal direction could be obtained. The arrangement of the radiation sources 1 on the radiation source carrier 2 is similar to FIG. 3 or FIG. 4, respectively. Only the longitudinal distances are chosen slightly differently. In the first group 12, the longitudinal distances between adjacent radiation sources 1 is 36 mm in each case. In the second 13 and third 14 group, the longitudinal distances between adjacent radiation sources 1 are 22 mm in each case. The longitudinal distance between adjacent groups 12, 13, 14 is 28 mm in each case.

(40) FIG. 9 shows simulation results for the irradiance on a cylindrical surface obtained with an exemplary embodiment of the illumination device 100. For this simulation, an illumination device 100 with five radiation emitting units 10 as described in connection with FIG. 3 was used. The radiation emitting units 10 were arranged around a cylinder with a diameter of 200 mm and a height of 300 mm. The radiation emitting units 10 were arranged such that the distance of the radiation output area 11 of each radiation emitting unit 10 to the cylinder surface was 125 mm. The upper picture of FIG. 9 shows the arrangement.

(41) The homogeneity of the irradiance on the cylinder surface was investigated as a function of the azimuthal angle (middle picture of FIG. 9). On the y-axis, the irradiance in arbitrary units is shown. On the x-axis the azimuthal angle is shown. The different data samples Z1 . . . Z5 correspond to measurements at different heights along the longitudinal direction L (see also upper picture of FIG. 9).

(42) In the lower picture of FIG. 9, the irradiance in arbitrary units (y-axis) is shown as function of the height along the longitudinal direction L (x-axis). The different data samples Z1 . . . Z6 correspond to measurements at different azimuthal angles.

(43) As becomes clear from FIG. 9, lower picture, the special arrangement of the radiation sources 1 on the respective radiation source carriers 2 of the radiation emitting units 10 results in a very homogeneous irradiance along the longitudinal direction L.

(44) In FIG. 9, middle picture, one can see that due to the configuration of the illumination device 100 with several radiation emitting units 10, which are pivotally connected to each other, and thus can be arranged around the cylinder with equal distances to the cylinder surface, a very homogenous irradiance along the azimuthal angle up to 90° is obtained.

(45) FIG. 10 shows an exemplary embodiment of a radiation source 1 being an optoelectronic component. All radiation sources 1 of the radiation emitting unit 10 or of the whole illumination device 100 are preferably formed identically within the manufacturing tolerance and may each be such an optoelectronic component.

(46) The optoelectronic component 1 comprises a semiconductor chip 1a, for example based on a III-V-compound semiconductor material. The semiconductor chip 1a is mounted on a front side of a ceramic chip carrier 1b. The chip carrier 1b may be pierced by through connections (not shown), electrically connecting metallic front side pads 1d on the front side with metallic rear side pads 1e on the rear side of the chip carrier 1b. The semiconductor chip 1a is electrically connected to the front side pads 1d. A thermal pad 1f, for example made of metal, on the rear side helps to remove heat from the optoelectronic component 1.

(47) The semiconductor chip 1a is embedded in a lens-shaped encapsulation 1c, which collimates the radiation coming from the semiconductor chip 1a. The encapsulation is, for example, made of transparent silicone.

(48) The properties of the optoelectronic component 1 are, for example, as follows: A peak wavelength of the emitted radiation is 634.0 nm when operated with an operation current of 350 mA and at an operation temperature of 25° C. An opening angle into which at least 75% of the radiation intensity is emitted is at most 80°. A main radiation direction is 0°, wherein the radiation direction is measured relative to a normal axis running perpendicularly to a main extension plane of the chip carrier 1b or to a radiation exit surface of the semiconductor chip 1a. The emission angle at which the radiance decreases from its maximum at 0° to 50% of the maximum value is at ±40°. The luminous efficacy is 111 lm/W.

(49) During operation of the illumination device 100, each optoelectronic component 1 is, for example, operated with an operation current of 1000 mA.

(50) FIG. 11 shows an exemplary embodiment of the method for treating a skin disease on the basis of a flow chart. In a step S1, a pharmaceutical substance is applied to the surface of the skin of a human being in a region which is to be treated. It might be the region in a face. The pharmaceutical substance is, for example, a photosensitizing drug or precursor to such a drug that is excitable by light in the radiation spectrum emitted by the illumination device 100. The pharmaceutical substance may comprise 5-aminolevulinic acid.

(51) In a step S2, the skin region to be treated is arranged in the predetermined object location 300 of the illumination device 100 (see FIG. 2).

(52) In a step S3, the skin region to be treated is irradiated with the illumination device, for example for at least 10 min and at most 20 min. During the illumination session, the skin region is irradiated with a predetermined light dose of, e.g., at least 30 and at most 45 J/cm.sup.2, such as 37 J/cm.sup.2. A light dose of 37 J/cm.sup.2 is especially suitable if red light with a wavelength of about 635 nm is used to irradiate the object. In case green or blue light is used, e.g. for irradiating a skin surface onto which ALA has been topically applied before the irradiation, the total light dose applied to the irradiation object during the illumination session may have a different value due to the different absorption properties for these wavelengths. The general teaching in the present disclosure does not only apply for light sources emitting red light but also for light sources of different colored light, e.g. blue or green light, particularly if ALA-based PDT is performed.

(53) The invention described herein is not limited by the description in conjunction with the exemplary embodiments. Rather, the invention comprises any new feature as well as any combination of features, particularly including any combination of features in the patent claims, even if said feature or said combination per se is not explicitly stated in the patent claims or exemplary embodiments.

(54) In the following, a set of embodiments is disclosed. The embodiments are numbered to facilitate referencing the features of one embodiment in other embodiments. The embodiments form part of the disclosure of the present application and could be made subject to independent and/or dependent claims irrespective of what currently is claimed in the application and also independent of the references in brackets. We note, however, that the scope of protection is defined by the appended claims, where the following embodiments do not constitute claims. The embodiments are:

Embodiments

(55) 1. Illumination device (100) for photodynamic therapy,

(56) the illumination device (100) comprising at least one electromagnetic radiation emitting unit (10),

(57) the at least one electromagnetic radiation emitting unit (10) comprising at least one electromagnetic radiation source (1),

(58) the electromagnetic radiation source (1) being configured to generate radiation for the irradiation of a region of an irradiation object (200) in an illumination session,

(59) wherein the irradiation object (200) is to be arranged at a predetermined object location (300),

(60) wherein the predetermined object location (300) is arranged at a distance relative to a radiation output area (11) of the radiation emitting unit (10) through which the radiation generated by the at least one electromagnetic radiation source (1) exits the radiation emitting unit (10) during operation of the illumination device (100).

(61) 2. Illumination device (100) according to embodiment 1,

(62) wherein the radiation emitting unit (10) comprises a plurality of radiation sources (1) arranged on a common radiation source carrier (2),

(63) wherein an occupancy density of the radiation source carrier (2) with radiation sources (1) is smaller in a center region of the radiation source carrier (2) than in peripheral regions of the radiation source carrier (2) outside the center region.

(64) 3. Illumination device (100) according to embodiment 2,

(65) wherein the radiation sources (1) are arranged in a one- or two-dimensional pattern on the radiation source carrier (2).

(66) 4. Illumination device (100) according to embodiment 3,

(67) wherein the pattern is irregular.

(68) 5. Illumination device (100) according to any of the embodiments 2 to 4,

(69) wherein the radiation source carrier (2) is an elongate carrier with a main direction of extension defining a longitudinal direction (L).

(70) 6. Illumination device (100) according to embodiment 3 or any of embodiments 4 and 5 in their dependency of embodiment 3,

(71) wherein the pattern is symmetrical relative to one axis or two axis, which are perpendicular.

(72) 7. Illumination device (100) according to any of the embodiments 2 to 6,

(73) wherein the radiation sources (1) on the radiation source carrier (2) are grouped into a plurality of groups (12, 13, 14), wherein the radiation sources (1) of each group (12, 13, 14) are arranged in a regular group pattern, wherein at least two groups (12, 13) of the plurality of groups have different group patterns.

(74) 8. Illumination device (100) according to embodiment 7,

(75) wherein at least two groups (13, 14) of the plurality of groups (12, 13, 14) have the same group pattern.

(76) 9. Illumination device (100) according to embodiment 8,

(77) wherein a first group (12) with a first group pattern is arranged between a second group (13) and a third group (14), when seen in plan view of the radiation source carrier (2),

(78) wherein the second (13) and the third (14) group have the same group pattern and the first group (12) has a different group pattern.

(79) 10. Illumination device (100) according to any of the preceding embodiments, wherein the radiation emitting unit (10) comprises a unit housing (3) which defines an outer edge (30) of the radiation emitting unit (10).

(80) 11. Illumination device (100) according to embodiment 10,

(81) wherein the radiation emitting unit (10) comprises a plurality of radiation source carriers (2), each radiation source carrier (2) being provided with a plurality of radiation sources (1),

(82) wherein the radiation source carrier (2) closest to the outer edge (30) is oriented such that a main radiation direction (V) of the radiation sources (1) on this radiation source carrier (2) is outwardly offset from a main radiation direction (V) of the radiation sources (1) on another radiation source carrier (2) further away from the outer edge (30).

(83) 12. Illumination device according to any of the preceding embodiments,

(84) wherein the radiation emitting unit (10) comprises one continuous radiation source carrier (2) common for all radiation sources (1) of the radiation emitting unit (10).

(85) 13. Illumination device according to any of the embodiments 1 to 10,

(86) wherein the radiation emitting unit (10) comprises a plurality of radiation source carriers (2), each radiation source carrier (2) being provided with a plurality of radiation sources (1), at least two radiation source carriers (2) being arranged angled relative to one another, wherein the radiation source carriers (2) are

(87) fixed in their relative position to one another or

(88) movable relative to one another.

(89) 14. Illumination device (100) according to any of the preceding embodiments,

(90) wherein the at least one radiation source (1) is an optoelectronic component,

(91) wherein the emission spectrum of the optoelectronic component has a peak wavelength in one of the following ranges: 635 nm±4 nm, 542 nm±4 nm, 506 nm±4 nm.

(92) 15. Illumination device (100) according to any of the preceding embodiments,

(93) wherein the illumination device (100) comprises a plurality of radiation emitting units (10) which are movably connected to one another.

(94) 16. Illumination device (100) according to any of the preceding embodiments,

(95) wherein the illumination device (100) comprises a location or distance monitoring system (4), wherein the monitoring system (4) is configured to monitor the location and/or the distance of the irradiation object (200) from the radiation emitting unit (10) and/or from the predetermined object location (300).

(96) 17. Illumination device (100) according to embodiment 16 in its dependency of embodiment 2, wherein

(97) the monitoring system (4) comprises a distance sensor (40) arranged on the radiation source carrier (2) of the at least one radiation emitting unit (10),

(98) the distance sensor (40) is located offset of a geometric center of the radiation source carrier (2) when viewed in plan view.

(99) 18. Illumination device (100) according to embodiment 17,

(100) wherein the illumination device (100) is configured to compensate for distance or location variations of the irradiation object (200) from the respective radiation emitting unit (10) and/or the predetermined object location (300) in order to maintain a predetermined radiation dose during the illumination session.

(101) 19. Illumination device (100) according to any of embodiments 16 to 18,

(102) wherein the monitoring system (4) is configured to adjust the operation of the illumination device (100) or to call for an adjustment of the operation of the illumination device (100) by using one of, an arbitrary combination of or all of the following measures:

(103) varying the distance between the respective radiation emitting unit (10) and the irradiation object (200),

(104) adjusting the radiation power emitted by the respective radiation emitting unit (10), and/or

(105) adjusting a duration of the illumination session.

(106) 20. A method for treating a skin disease comprising the following steps:

(107) a) applying a pharmaceutical substance to the surface of the skin in a region which is to be treated;

(108) b) arranging the skin region to be treated in a predetermined object location (300) of the illumination device (100) according to any of the preceding embodiments,

(109) c) irradiating the skin region to be treated with the illumination device (100).

(110) 21. A method for operating an illumination device (100) according to any of the embodiments 1 to 19, comprising the steps of:

(111) providing a measurement signal which is indicative for a distance between the radiation emitting unit (10) and the radiation object (200),

(112) generating an operation signal as a function of the measurement signal, said operation signal being configured to cause the illumination device (100) to adjust the operation of the illumination device (100) or to call for an adjustment of the operation of the illumination device (100).

(113) 22. Computer program product comprising machine-readable instructions, which, when loaded and executed on a processor, are configured to cause the illumination device to execute the method of embodiment 21.

(114) 23. A computer-readable medium having stored thereon the computer program product according to embodiment 22.

(115) This patent application claims the priority of the U.S. patent application Ser. No. 17/071,496, the disclosure content of which is hereby incorporated by reference.

REFERENCE SIGN LIST

(116) 1 radiation source 2 radiation source carrier 3 unit housing 4 monitoring system 10 radiation emitting unit 10a . . . 10e graphical representations of radiation emitting units 11 radiation output area 12 first group 13 second group 14 third group 15 hinge 20 carrier edge 30 outer edge 40 distance sensor 41 electronic control unit 42 motor 43 connector 44 connector 45 graphical user interface 100 illumination device 200 irradiation object 300 object location L longitudinal direction T transversal direction V main radiation direction A1. . . A5 data samples Z1 . . . Z6 data samples S1 . . . S3 method steps