IMAGING DEVICE FOR A MEDICAL IMAGING SYSTEM, MEDICAL IMAGING SYSTEM AND METHOD FOR GENERATING MEDICAL IMAGES

Abstract

The present invention relates to an imaging device (1) for a medical imaging system (100), comprising: at least one first photosensitive imaging member (10), at least one second photosensitive imaging member (20), and an optical element (30),

wherein the optical element (30) is configured to route an incoming image to the first photosensitive imaging member (10) and/or the second photosensitive imaging member (20).

Claims

1. Imaging device (1) for a medical imaging system (100), comprising: at least one first photosensitive imaging member (10), at least one second photosensitive imaging member (20), and an optical element (30), wherein the optical element (30) is configured to route an incoming image to the first photosensitive imaging member (10) and/or the second photosensitive imaging member (20).

2. Imaging device (1) according to claim 1, wherein the optical element (30) is a beam splitter and/or movable between a position in an optical path (5) of the incoming image and a position outside of the optical path (5).

3. Imaging device (1) according to claim 2, wherein the beam splitter is switchable between an active state to at least partially route the incoming image to the first photosensitive imaging member (10) and the second photosensitive imaging member (20), and an inactive state to route the incoming image to the first photosensitive imaging member (10) or the second photosensitive imaging member (20).

4. Imaging device (1) according to claim 2, wherein the beam splitter is a wavelength-selective optical element.

5. Imaging device (1) according to claim 1, wherein the first photosensitive imaging member (10) provides an imaging spectrum different from the second photosensitive imaging member (20).

6. Imaging device (1) according to claim 5, wherein the first photosensitive imaging member (10) is a color imaging member and the second photosensitive imaging member (20) is a black and white imaging member for light outside a visible range or a color imaging member with higher sensitivity for predetermined colors.

7. Imaging device (1) according to claim 1, wherein a filter device (11, 21) is arranged between the optical element (30) and the first photosensitive imaging member (10) and/or the optical element (30) and the second photosensitive imaging member (20).

8. Imaging device (1) according to claim 7, wherein the filter device (11, 21) comprises at least two filters and the filter device is configured to allow a change of the position of the filters to selectively provide different filter characteristics.

9. Medical imaging system (100), comprising: at least one imaging device (1) according to claim 1 and an image processing unit (50), wherein the image processing unit (50) is configured to receive images from the first photosensitive imaging member (10) and the second photosensitive imaging member (20).

10. Medical imaging system (100) according to claim 9, wherein the image processing unit (50) is capable of combining images from the first photosensitive imaging member (10) and the second photosensitive imaging member (20).

11. Medical imaging system (100) according to claim 9, wherein the imaging system (100) further comprises a control unit (60) to control an exposure time and/or an exposure rate of the first photosensitive imaging member (10) and/or the second photosensitive imaging member (20), or wherein the first photosensitive imaging member (10) and the second photosensitive imaging member (20) provide an exposure time and/or an exposure rate different from each other.

12. Medical imaging system (100) according to claim 11, wherein the image processing unit (50) is capable of assigning respective images of a lower exposure rate and/or higher exposure time of the first photosensitive imaging member (10) or the second photosensitive imaging member (20) to a plurality of images of a higher exposure rate and/or lower exposure time of the respective other photosensitive imaging member (10, 20).

13. Medical imaging system (100) according to claim 9, wherein the imaging system (100) comprises at least two imaging devices (1), and wherein the image processing device (50) is capable of combining images of the first photosensitive imaging members (10) and/or the second photosensitive imaging members (20) of the respective imaging devices (1), preferably provided to the image processing unit (50) via one input cable.

14. Method for generating medical images, the method comprises: routing an image via an optical element (30) to a first photosensitive imaging member (10) and a second photosensitive imaging member (20), providing image data of a different imaging spectrum by each of the first photosensitive imaging member (10) and the second photosensitive imaging member (20), and combining the image data to a combined image.

15. Method according to claim 14, wherein the method further comprises assigning different exposure times and/or exposure rates to the first photosensitive imaging member (10) and the second photosensitive imaging member (20).

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

[0047] FIG. 1 is a schematic cross-sectional view of an image device and optical path of an incoming image according to an exemplary embodiment; and

[0048] FIG. 2 is a schematic view of an exemplary imaging system comprising two imaging devices according to FIG. 1.

DESCRIPTION OF SPECIFIC EMBODIMENTS OF THE INVENTION

[0049] FIG. 1 shows a schematic cross-sectional view of an image device 1 and optical path 5 of an incoming image according to an exemplary embodiment. The incoming image passes through an objective 40 and is directed to an optical element 30. Here, the optical element 30 is a semi-transparent wavelength-selective mirror, configured to reflect wavelengths in the visible region to a first photosensitive imaging member 10 and to transmit wavelengths in the non-visible region to a second photosensitive imaging member 20. However, in alternative embodiments, the optical element may not be wavelength-selective and a wavelength-selection of wavelengths to be received by a photosensitive imaging member may be provided by filter devices arranged between the optical element and respective photosensitive imaging member, as described later. The semi-transparent parallel surfaces of the optical element 30 are tilted by 45° with respect to a plane perpendicular to the optical path 5 extending from the objective 40. In other words, an end of the optical element 30 facing the objective 40 forms an angle of 45° with the incoming optical path 5. The semi-transparent surface of the optical element 30 facing the objective is defined as facing side of the optical element. Alternatively to the semi-transparent wavelength-selective mirror, an optical element splitting the incoming beam into two beams with a predetermined intensity ratio, e.g. 50:50, may be used. However, with the first and second photosensitive imaging members providing different imaging spectra, as described later, a semi-transparent wavelength-selective mirror may provide higher intensities for the first and second photosensitive imaging members in accordance with a respective imaging spectrum.

[0050] An imaging side of first photosensitive imaging member 10 is facing the facing side of the optical element 30. The imaging side of first photosensitive imaging member 10 is arranged perpendicular to the beam reflected by the optical element 30. The first photosensitive imaging member 10 is a CMOS sensor for white light with four color pixels. A first filter device 11 is disposed in the optical path 5 of the reflected beam between the optical element 30 and the first photosensitive imaging member 10. The first filter device 11 comprises a filter configured to filter wavelengths that may cause noise with respect to the image data to be recorded by the first photosensitive imaging member 10. In alternative embodiments, as already addressed above, the first filter device may not only reduce noise but may be configured as a wavelength-selective member as such.

[0051] An imaging side of the second photosensitive imaging member 20 is facing the side of the optical element 30 opposed to the facing side of the optical element 30. The imaging side of the second photosensitive imaging member 20 is arranged perpendicular to the beam transmitted by the optical element 30. The second photosensitive imaging member 20 is a black and white CMOS-sensor sensitive for fluorescence light. For example, the emission spectrum of 5-ALA (aminolevulinic acid) is in a range of 600 nm to 750 nm, of ICG (incocyanine green) in a range between 750 nm to 950 nm, and of fluorescein of about 520 nm. Here, the second photosensitive imaging member 20 is configured to be sensitive to 5-ALA fluorescence. However, in alternative embodiments, other sensitivities may be provided depending on the respective emission spectrum. In particular, the second photosensitive imaging device may be configured to provide a broad wavelength photosensitivity to be applicable for a broad range of applications.

[0052] Similar to the first filter device 11, a second filter device 21 is disposed in the optical path 5 of the transmitted beam between the optical element 30 and the second photosensitive imaging member 20. The second filter device 21 comprises a filter configured to filter wavelengths that may cause noise with respect to the image data to be recorded by the second photosensitive imaging member 20. With respect to 5-ALA fluorescence, the second filter device 21 is configured to transmit wavelength within a range of 630 nm+/−15%, representing an emission maximum of 5-ALA. Accordingly, a wavelength selection is provided by the second filter device that does not only reduce noise but also cut-off wavelengths not intended to be images, irrespective of a further photosensitivity of the second photosensitive imaging member 20.

[0053] In alternative embodiments, the first and/or second filter device may be configured as a revolver head unit with several filters arrangeable around a rotational axis of a revolver head. The filters may also be arrangable in different axial positions with respect to the rotational axis of the revolver head. Accordingly, different filters may be exchangeable and may be selectively or simultaneously arranged in front of the respective photosensitive imaging member. Due to the use of different filters, the imaging spectrum of the photosensitive imaging members may be adapted. Similarly, the photosensitive imaging members may be electronically controlled to adapt a respective imaging spectrum. For example, the photosensitive imaging member may provide several different pixels in an array that may be activated or deactivated in correspondence with a predetermined imaging spectrum.

[0054] FIG. 2 is a schematic view of an exemplary imaging system 100 comprising two imaging devices 1 according to FIG. 1. The imaging system 100 further comprises an image processing unit 50, a control unit 60 and a display unit 70.

[0055] The control unit 60 is configured to control the image processing unit 50, the display unit 70 and the imaging devices 1. Here, the control unit 60 is provided together with the image processing unit 50. In alternative embodiments, the control unit may be provided as or by a separate unit. With respect to the signal connections, indicated by the solid double arrows in FIG. 2, image data of the imaging devices 1 is transmitted to the image processing unit 50. In turn, the image processing unit 50 or the control unit 60, respectively, transmits control signals to the imaging devices 1. The control signals may comprise image settings like exposure times and/or exposure rates or drive signals for a movement of the imaging devices. According to the present embodiment, the data transfer between the imaging devices 1 and the image processing unit 50 or control unit 60, respectively, is implemented by a single cable branched to each of the imaging devices 1. Alternatively or in addition, data transfer may be provided wirelessly according to other exemplary embodiments. Further, the image data processed by the image processing unit 50, as described later, is transferred to the display unit 70. The image data may be accompanied by further display control signals. According to the exemplary embodiment, the display unit 70 comprises a touchscreen to also serve as input device for control commands to be transferred to the image processing unit 50 or control unit 60, respectively.

[0056] Each of the imaging devices 1 is oriented in a predetermined orientation with respect to an object to record images thereof. The predetermined orientations correspond to a recording of images suitable for generating three-dimensional images of the object by processing the image data of each of the imaging devices 1 transferred to the image processing unit 50. Accordingly, the image processing unit 50 is configured to combine the image data received by the imaging devices 1 to generate a three-dimensional image. The image processing unit 50 transmits such three-dimensional image to the display unit 70 to be displayed. In alternative embodiments, a three-dimensional image may be provided by directing images of the respective images devices to different display areas, e.g. an imaging display area of a head-mounted display representing a left eye and an imaging display area of the head-mounted display system representing a right eye. The image processing unit 50 and the display unit 70 are also configured to display two-dimensional images according to the processed data of the imaging devices alternatively or in addition in response to the display settings or a respective input by an operator.

[0057] Further, the image processing unit 50 is configured to process image data of the first and second photosensitive imaging members 10, 20 of each of the imaging devices 1 to generate a combined image of the process image data of the first and second photosensitive imaging members 10, 20 of each of the imaging devices 1. If two-dimensional images are intended to be displayed in addition or alternatively to three-dimensional images, the image processing unit 50 processes the image data of the respective images devices 1 separately to generate a combined image of each of the imaging devices 1. The respectively processed image data may be processed further to be combined to provide a three-dimensional image, if required. However, if only a three-dimensional image has to be displayed, the image processing unit 50 is configured to process the image data of both imaging devices 1 at once. Additionally, the image processing unit 50 is configured to process the data of the first photosensitive imaging member 10 and/or the second imaging member 20 of each or only one of the imaging devices 1 according to respective display settings. In principle, each processing with respect to any display settings or displaying images in general may also apply for storing images alternatively or in addition, e.g. for documentation purposes.

[0058] According to the exemplary embodiment with the first photosensitive imaging member 10 of each of the imaging devices 1 being a CMOS-sensor for white light and the second photosensitive imaging member 20 of each of the imaging devices 1 being a black and white CMOS-sensor sensitive for fluorescence light, the control unit 60 controls an exposure time for each of the first and second photosensitive imaging members 10, 20. To reduce the required light intensity for fluorescence images, the exposure time of the second photosensitive imaging members 20 is controlled to be twice the exposure time of the first photosensitive imaging members 10. The control unit 60 is configured to control the exposure times such that two images by the first photosensitive imaging member 10 and one image by the second photosensitive imaging member 20 are captured in one time interval. Accordingly, the image processing unit 50 is configured to assign the image data of the one image captured by the second photosensitive imaging member 20 to each of the image data of the two images captured by the first photosensitive imaging member 10 in such time interval to generate combined images. In alternative embodiments, the control device may be configured to adapt the exposure times of the first and second photosensitive imaging members 10, 20 to be equal to each other or three times, four times or otherwise different from each other.

[0059] In summary, the imaging system 100 according to the exemplary embodiment is capable of displaying and/or storing images of each of the first and second photosensitive imaging members 10, 20 of the imaging devices 1 separately, combined images of the first and second photosensitive imaging members 10, 20 of each of the imaging devices 1, combined images of images of the first and/or second photosensitive imaging members 10, 20 of one imaging device 1 combined with images of the first and/or second photosensitive imaging members 10, 20 of the other imaging device 1.

[0060] It is to be noted that the given examples are specific embodiments and not intended to restrict the scope of protection given in the claims. In particular, single features of one embodiment may be combined with another embodiment. As an example, even though the imaging devices according to the exemplary embodiment provide the same configuration, the present invention is not limited thereto. The first and/or second photosensitive imaging members of one imaging device may differ from the first and/or second photosensitive imaging members of the other imaging device or may be controlled differently. Further, the imaging system is not restricted to providing two imaging devices but may also comprise only one or more than two imaging devices. In another variant, at least one imaging device may comprise an image pre-processing unit to allow a reduction of the amount of signals to be transmitted to an external processing unit to a required minimum.

LIST OF REFERENCE SIGNS

[0061] 1 imaging device [0062] 5 optical path [0063] 10 first photosensitive imaging member [0064] 11 first filter device [0065] 20 second photosensitive imaging member [0066] 21 second filter device [0067] 30 optical element [0068] 40 objective [0069] 50 image processing unit [0070] 60 control unit [0071] 70 display unit [0072] 100 imaging system