Abstract:
A method is described for displaying an image of an illumination field of a medical operation. The method includes recording an image at an illumination field of an operation, receiving a color temperature signal representative of an operating lamp that illuminates the illumination field of the operation, based on the received color temperature signal, adjusting parameters to compensate for differences in the received color temperature signal from white balance to produce a white balanced image, and outputting the white balanced image to a monitor.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims priority under 35 U.S.C. §119(a) to German Application No. 20 2007 007 054.3, filed on May 15, 2007, the entire contents of which are hereby incorporated by reference. 
       TECHNICAL FIELD 
       [0002]    The invention relates to a system including an operating lamp whose color temperature can be adjusted using a controller, and a camera for recording the operation that is illuminated by the operating lamp. 
       BACKGROUND 
       [0003]    Digital cameras generally include a light-sensitive sensor, on which an image is imaged by means of optics. The incident light is converted into a charge in the sensor (for example, a charge-coupled device (CCD) sensor or a CMOS sensor), which is converted into a voltage value at a further stage. The voltage generated in this fashion is proportional to the incident quantity of light. 
         [0004]    For detecting and representing a color image, the individual colors are detected selectively. For example, a three-chip camera can be used to separate the light into the corresponding red, green, and blue components with a beam splitter prism. The three-chip camera includes three sensors (or chips). Each of the beams separated from the prism is guided to a separate sensor, and each of the sensors represents the red, green, and blue components, respectively, of the incident light as separate voltage signals. 
         [0005]    As another example, a one-chip camera can be used to detect a color image. The one-chip camera includes only one sensor (or chip); therefore, the color-selective detection of the incident light is obtained by color filters disposed on the pixels. In this fashion, different, microscopically small filters are disposed on the individual pixels, thus ensuring that each pixel is exposed to only one defined color component. In the one-chip camera, neighboring pixels are provided with different color filters in order to be able to regenerate the actual color of the image area in a downstream processing step. The downstream electronics calculates a color value for the respective area from the color components of the directly neighboring pixels. 
         [0006]    The color temperature of operating lamps can be adjusted to improve the distinguishability of different types of tissue. The white light then tends to have components in a range from red to blue. If a video camera were used to transmit the image from the operating area, the resulting image would have a reddish to bluish color in dependence on the setting of the operating lamp. 
       SUMMARY 
       [0007]    In one general aspect, an operating system includes an operating lamp for illuminating an illumination field of a medical operation, and a camera for recording an image at the illumination field. The operating lamp has a color temperature that is adjustable using a controller. A signal indicating the color temperature of the operating lamp is transmitted to the camera. 
         [0008]    Implementations can include one or more of the following features. For example, the camera can be connected to the controller of the operating lamp through a data line. The color temperature signal can be transmitted from the controller to the camera. 
         [0009]    The system can include a sensor that is configured to detect the color temperature at the illumination field. The color temperature signal can be transmitted from the sensor to the camera. The sensitivity of the sensor can be adjustable. 
         [0010]    The camera can include memory for storing the color temperature signal. The camera can be housed in a handle of the operating lamp. The camera can be disposed on a support arm of the operating lamp. The camera can be integrated in a light module of the operating lamp. 
         [0011]    The color temperature signal can be transmitted cyclically to the camera. The color temperature signal can be transmitted to the camera after the color temperature is adjusted by the controller. 
         [0012]    The camera can adjust parameters to compensate for differences in the color temperature signal from white balance to produce a white balanced image. 
         [0013]    The system can include a monitor connected to the camera to receive the white balanced image from the camera and to display the white balanced image. 
         [0014]    In another general aspect, a method of performing a medical operation on living tissue is described. The method includes illuminating the tissue with an operating lamp that has a color temperature, adjusting the color temperature of the operating lamp with a controller, recording an image of the tissue with a camera, and transmitting a signal representing the color temperature of the operating lamp to the camera. 
         [0015]    Implementations can include one or more of the following features. For example, the method can also include outputting a white balanced image from the camera to the monitor. The color temperature signal can be transmitted to the camera from the controller. 
         [0016]    The color temperature signal can be transmitted to the camera from a sensor that is configured to detect the color temperature at the illumination field. The sensitivity of the sensor can be adjustable. 
         [0017]    The method can also include storing the color temperature signal in the camera. 
         [0018]    The color temperature signal can be transmitted cyclically to the camera. The color temperature signal can be transmitted to the camera after the color temperature is adjusted by the controller. 
         [0019]    In another general aspect, a method is described for displaying an image of an illumination field of a medical operation. The method includes recording an image at an illumination field of an operation, receiving a signal representative of a color temperature of an operating lamp that illuminates the illumination field of the operation, based on the received color temperature signal, adjusting parameters to compensate for differences in the received color temperature signal from white balance to produce a white balanced image, and outputting the white balanced image to a monitor. 
         [0020]    Implementations can include one or more of the following features. For example, receiving the signal representative of the color temperature can include receiving the color temperature signal from a controller of the operating lamp. Receiving the signal representative of the color temperature can include receiving the color temperature signal from a sensor that is configured to detect the color temperature at the illumination field. 
         [0021]    The method can also include storing the color temperature signal. 
         [0022]    Receiving the color temperature signal can include cyclically receiving the color temperature signal. Receiving the color temperature signal can include receiving the color temperature signal after the color temperature is adjusted by a controller of the operating lamp. 
         [0023]    In general, the camera in the operating system described herein performs automatic white balance of the image from the operating area. The operating system therefore includes a means for transmitting the (adjusted) color temperature (that is, a signal that represents the color temperature of the operating lamp) to the camera. The information about the color temperature of the operating lamp (or the color temperature at the operating area) is transmitted to the camera. The camera can correspondingly adjust its white balance parameters. 
         [0024]    For application in the field of the lamp family, described, e.g., by EP 1722157 A1, the color temperature is generated by the different weighting with light sources emitting different spectra. The process control that initiates this weighting has this information. These processors therefore precisely control the color temperature to be emitted from the operating lamp. 
         [0025]    The color temperature (and therefore any adjustments of the color temperature) of the operating lamp are thus known and can be transmitted to electronics within the camera through an interface/data line. The camera receives the signal representing the color temperature and can adjust its internal balancing characteristic in correspondence with these values. This ensures direct adjustment of the camera to the color temperature at the operation area, thereby guaranteeing true-color reproduction of the imaged operating area. 
         [0026]    The operating lamp has illuminants of different colors, and the operating lamp can change the color temperature within a range from about 3500K to about 5000K. When the color temperature changes, the light intensity of the operating lamp and the color reproduction remain almost constant. When the color temperature changes, the light intensity of the operating lamp remains constant. 
         [0027]    The illuminants of the operating lamp and their drive units are calibrated such that the color temperature target specifications of the control exactly correspond with the actual values. 
         [0028]    The color temperature (which can be an adjusted color temperature) is transmitted to the camera, either cyclically or only in case of a change, via serial connection (such as an RS485 bus) via a special protocol or by means of another data transfer. The camera includes a means for storing the values relating to sensitivity or amplification of the sensor portions for the individual colors. The values stored in the camera are then fetched by means of information from the operating lamp, and processing of the sensor signals is correspondingly driven. 
         [0029]    The adjusted or emitted color temperature can alternatively be detected by a sensor and then be transmitted to the camera. The sensor can be integrated in the camera. The sensitivity of the color temperature sensors can alternatively be adjustable in order to improve detection of different colors. In this connection, it is, e.g., possible to distinguish tissue with increased blood supply (e.g., tumor cells) from tissue with less blood supply. The setting of the sensitivities can be stored either in fixed steps or can be continuous. 
         [0030]    Further advantages of the invention can be extracted from the description and the drawings. The features mentioned above and below can be utilized individually or collectively in arbitrary combination. The embodiments shown and described are not to be understood as exhaustive enumeration but have exemplary character for describing the invention. 
     
    
     
       DESCRIPTION OF THE DRAWINGS 
         [0031]      FIG. 1  is a schematic diagram of an operating lamp; 
           [0032]      FIG. 2  is a schematic diagram of a first system including an operating lamp and a camera; 
           [0033]      FIG. 3 , is a schematic diagram of a light module that can be used in the operating lamp of  FIG. 1 ,  2 ,  4 , or  5 ; 
           [0034]      FIG. 4  is a schematic diagram of a second system including an operating lamp and a camera; 
           [0035]      FIG. 5  is a schematic diagram of a third system including an operating lamp and a camera; and 
           [0036]      FIG. 6  is a schematic diagram of a fourth system including an operating lamp and a camera. 
       
    
    
     DETAILED DESCRIPTION 
       [0037]    Referring to  FIG. 1 , an operating lamp  1  includes a lamp body  2  having an inner space that houses a light source. The lamp  1  is an “operating” lamp in this it is used to illuminate a medical procedure. The output of the operating lamp  1  can be controlled by the surgeon who performs the medical procedure to ensure suitable light during or throughout the medical procedure. 
         [0038]    The lamp body  2  can be mounted on a support arm (such as a holder on a ceiling or wall of a building or mobile unit), such that it can be pivoted using a pivot arm of the support arm (an element  4  of which is shown in  FIG. 1 ). The operating lamp  1  can be moved and pivoted in three dimensions. Additionally, the lamp  1  includes a handle  3  mounted to the lamp body  2  to permit positioning of the operating lamp  1  at any location above an operating table. The handle  3  can be detachably disposed on a lower side  5  of the operating lamp  1 . Light is emitted on the lower side  5  of the lamp  1  to illuminate the location to be operated on. 
         [0039]      FIG. 2  shows an operating system  200  that incorporates the operating lamp  1 . The operating lamp  1  includes individual light modules  6   a - 6   g  that are assembled to form a light source. The light produced by the light modules  6   a - 6   g  is indicated through broken lines by light beams  7 , which generate a field of illumination  8   a . The field of illumination  8   a  can be the surface on the operating table that is illuminated. The light from the light modules  6   a - 6   g  can be combined to form various light sources such that the size, shape, and intensity of the illumination field  8   a  can be changed depending on the combination of light modules  6   a - 6   g.    
         [0040]    Referring also to  FIG. 3 , an individual light module  6   a  includes a housing  9 , the side surfaces of which have mechanical, electronic, and also electric connecting elements or connectors for driving illuminants in the light modules and connecting them to an electric power supply. The side surfaces can enable connection of the light module  6   a  with a neighboring light module  6   c ,  6   f , or  6   b . The light modules  6   a - 6   g  can be shaped so that they can be disposed on a spherical surface of a typical radius of 1000 mm without forming gaps between the light modules  6   a - 6   g . Additionally, the optical axis of each light module  6   a - 6   g  can generally face the focus of the spherical surface. The light modules  6   a - 6   g  each include illuminants such as light emitting diodes (LEDs), halogen lamps, gas discharge lamps, incandescent lamps, and liquid crystals. As shown in  FIG. 3 , for example, the light module  6   a  includes three LEDs  10   a - 10   c , each of which is associated with an optical element  11   a - 11   c  (such as a lens element) to produce respective light beams  12   a - 12   c . However, each light module  6   a - 6   g  can have It is possible to generate different illumination field shapes by disposing modules next to each other with changed angle of incidence. Intermediate elements such as the optical elements  11   a - 11   c  can be used for this purpose. 
         [0041]    Each light module  6   a - 6   g  has several, for example, 30 to 50, uniformly distributed LEDs. In order to ensure that the light is emitted in two dimensions, the optical path of the LEDs that emit light in an almost point shape is widened to the light emitting surface at the lower side  5  by the optical elements, and the optical path is guided from there into the illumination field. Towards this end, each LED is associated with the optical element. 
         [0042]    The light modules  6   a - 6   g  can be coupled to each other at any side surface, such that any combination is feasible. Therefore, it is possible to generate a lamp  1  whose illumination field is adjusted to the operation to be performed.  FIG. 2  shows one example of adjusting the light modules  6   a - 6   g  in order to adjust the illumination field  8   a  through the light beams  7 . Depending on the combination of the light modules  6   a - 6   g , the illumination field  8   a  can have a larger longitudinal extension or a larger width. The illumination field  8   a  can be differently formed at its edges or in its center. This means that the illumination field  8   a  reflects the contour of the light module combination. Each individual light module  6   a  can illuminate a complete operating location. The light modules  6   a - 6   g  can be arbitrarily combined with further light modules to form the most different overall modules as the light source. This changes the size of the illumination field, the illumination intensity, and the shape of the illumination field  8   a.    
         [0043]    The light modules  6   a - 6   g  need not be rigidly connected to each other; instead, the light modules  6   a - 6   g  are pivotably coupled to each other by way of articulated links. These links render the light modules  6   a - 6   g  pivotable, such that the surfaces at the lower side  5 , where the light is emitted, can be folded towards each other. 
         [0044]    In addition to or as an alternative to providing hinge-like joints at respective connecting lines of the light modules  6   a - 6   g , ball joints can be provided in one or more of the six corners of the light modules  6   a - 6   g . The joints permit later adjustment of the position of previously combined light modules  6   a - 6   g  relative to each other. In addition thereto, the operating surgeon can vary the illumination fields. 
         [0045]    The individual light modules  6   a - 6   g  form together a light source with a color temperature of approximately 3500 K to 5000 K, and a color reproduction index Ra&gt;93 in order to obtain a natural representation of the color, e.g., of the tissue to be operated on. For this reason, in addition to LEDs (such as, for example, LED  10   a  in light module  6   a ) generating white light, other LEDs (such as, for example, LEDs  10   b, c ) generating color light are used. A drop in the spectrum that would happen if only white LEDs were used, is prevented by admixing color light components such as cyan and blue. With a constant brightness of the white LEDs (for example, LED  10   a ), the color temperature and color reproduction of the mixed light generated by the light source consisting of all individual light modules  6   a - 6   g  can be variably adjusted through exclusively continuous dimming of the intensity of the color LEDs (for example, LEDs  10   b  and  10   c ). The luminous flux intensity of the color LEDs can be continuously changed. 
         [0046]    The LEDs (such as LEDs  10   a ,  10   b ,  10   c ) are connected to a controller  20  through power supply lines  13  (for example, through lines  13   a ,  13   b ,  13   c  shown in  FIG. 3 ), which permits electric dimming of the luminous flux of the LEDs. Electric dimming of the color LEDs (for example, LEDs  10   b  and  10   c ) results in a change or adjustment of color temperature and/or the color reproduction, which is advantageous for illuminating the operating location. It is thereby feasible for the operating surgeon to utilize the adjustability in such a fashion that he/she mixes color light and white light in dependence on his/her requirements in order to highlight special tissue types or tissue changes in a light-specific fashion. This makes it easier for the operating surgeon to identify individual tissue types or tissue changes. 
         [0047]    It is possible to set a basic color temperature of 4500 K that is automatically generated when the operating lamp  1  is switched on. The operating surgeon can individually adjust other desired color temperatures with the aid of a control panel or a keyboard of the controller  20  in dependence on the application of the operating lamp. The required adjustment parameters can be stored in a storage of the controller  20 . In another feasible variant, the operating surgeon can additionally store further settings chosen by him/her, and also change these settings at a later time. 
         [0048]    The operating system  200  includes a camera system  30  having a camera  31  and a housing  32 . The camera system  30  can be mounted in one of one of the light modules, i.e., the central light module  6   f  of the operating lamp  1  can bear the camera system  30 . The camera  31  can be a video camera or a still photography camera. Additionally, the camera  31  can be configured to record either or both still images and videos. 
         [0049]    When the camera system  30  is inserted into the central light module  6   f , the required electrical connections and the connections suitable for image processing are automatically established between the camera system  30  and other components through a data line  50 . The camera housing  32  can be the handle  3  of the operating lamp  1  so that the camera  31  is mounted within the operating lamp  1  handle  3 . 
         [0050]    The camera system  30  should be positioned so that it has a view of the operating area (that is, from the illumination field  8   a ) so that the camera system  30  can transmit an image from the operating area. The camera system  30  is connected to a monitor  80  that is positioned in the operating room or at any other location, such as, e.g., an auditorium, conference rooms, or offices of physicians who are online. 
         [0051]    In one implementation, the camera  31  is connected to the controller  20  of the operating lamp  1 . The camera  31  can be a one-chip, three-chip, or any suitable digital camera that produces color. The color temperature of the operating lamp  1  can be automatically transmitted to electronics within the camera  31  through the data line  50  and from the controller  20  (which stores the color temperature). 
         [0052]    The data can be transmitted to the camera  31  cyclically or only when a change in the color temperature occurs. The data can be transmitted by any suitable means of data transfer or protocol, such as, for example, through an RS 485 bus. The electronics within the camera  31  include a processor and memory for storing information for use by the processor. The memory stores values relating to the sensitivity or amplification of the sensor portions for the individual colors (where the sensor portions can be individual pixels or each chip, depending on whether the camera  31  is a one-chip or a three-chip camera. The memory can also store applications for operation by the processor. The camera  31  (and in particular, the electronics within the camera  31 ) receives the color temperature and adjusts its internal balancing characteristics relative to the color temperature. In this way, the camera  31  directly adjusts its output to the monitor  80  to be a true-color reproduction of the imaged operating area. Moreover, the parameters for white balance of the camera  31  can be correspondingly adjusted. White-balanced images can be displayed on the monitor  80 . 
         [0053]    It is also feasible to dispose the camera system  30  at any other location of the operating lamp  1 . 
         [0054]    For example, as shown in  FIG. 4 , the camera system  30 ′ including the camera  31 ′ is provided on a support arm  90  of the operating lamp system. 
         [0055]    As another example as shown in  FIG. 5 , the camera  31 ″ is integrated in a light module such as the light module  6   b . For example, the camera  31 ″ can be positioned at, near, or within the housing  9  and the electronics of the camera  31 ″ can be within the housing  9 . 
         [0056]    Although not shown, the data line  50 , the controller  20 , and the monitor  80  (shown in  FIG. 2 ) are coupled to the light modules and the camera system and the cameras in  FIGS. 4 and 5 . 
         [0057]    Referring to  FIG. 6 , in another implementation, the color temperature of the operating lamp  1  or the color temperature at the illumination field  8   a  can be detected by one or more sensors  52  and then transmitted to the camera  31  by a data line  54 . In this implementation, therefore, the camera  31  need not acquire data directly from the controller  20 . The one or more color temperature sensors  52  can be integrated within the camera system  30  or can be mounted external to the camera system  30  (as shown in  FIG. 6 ). In any case, the sensors  52  are configured to view the illumination field  8   a . The sensitivity of the one or more sensors  52  can be adjusted depending on the detection of certain colors. For example, the one or more sensors  52  can be configured to be sensitive enough to distinguish tissue with increased blood supply from tissue with less blood supply. The sensitivity can be adjusted either in fixed steps or continuously. 
       OTHER EMBODIMENTS 
       [0058]    It is to be understood that while the invention has been described in conjunction with the detailed description thereof, the foregoing description is intended to illustrate and not limit the scope of the invention, which is defined by the scope of the appended claims. Other aspects, advantages, and modifications are within the scope of the following claims.