Abstract:
The invention relates to a method and a system for reducing anxiety of patients before and during e.g. MR scanning examinations. The method is based on displaying images on walls ( 106,107 ) of the scanner room ( 100 ) so that when the patient enters the scanner room, then an image is displayed on a wall visible to the patient, e.g. a wall adjacent to the entry door ( 103 ). When the patient is laying on the table ( 102 ) of the scanner ( 101 ) the projection of images is switched to another wall by reflecting the projected images using e.g. a mirror which is moved into the light rays emitted by an image projector.

Description:
FIELD OF THE INVENTION 
       [0001]    The invention relates to systems and methods for reducing anxiety of patients, in particular to systems suited for use in scanner rooms. 
       BACKGROUND OF THE INVENTION 
       [0002]    Patients that undergo scanning examinations, for example MR scans, are often highly stressed. The long and narrow tunnel of MR scanners creates a feeling of confinement and, therefore, increases anxiety or induces claustrophobia type symptoms. 
         [0003]    The quality of scanning results may be negatively affected if a patient is highly anxious. Therefore, in order to improve scanning results or at least for improving the comfort of patients there is a need for reducing or compensating patient&#39;s negative experience of scanners and scanner rooms. 
         [0004]    U.S. Pat. No. 6,774,929 discloses an MR video system that provides visual stimuli to a patient who is undergoing diagnostic treatment within a magnetic resonance imagery (MR) apparatus. The system utilizes a magnetically inert and RF shielded projector located in the close proximity to the MR apparatus to transpose a video picture on a translucent screen inside the bore of the MR apparatus. The patient views the screen through a prism. 
         [0005]    Whereas U.S. Pat. No. 6,774,929 discloses a system which may improve the comfort of patients in scanner rooms, the inventor of the present invention has appreciated that improvements for improving patient comfort are needed, and has in consequence devised the present invention. 
       SUMMARY OF THE INVENTION 
       [0006]    It would be advantageous to achieve improvements for reducing anxiety of patients both before and during scanning examinations. In particular, it may be seen as an object of the present invention to provide a method that solves the above mentioned problems caused by scanners, or other problems, of the prior art. 
         [0007]    To better address one or more of these concerns, in a first aspect of the invention an image projection system for use in a scanner room for patient examination is presented where an image projector is installed in the scanner room for projecting an image onto a surface of the room, the image projection system comprises 
         [0008]    a reflector unit comprising a reflector, where the reflector is positioned relative to the image projector so that in a first mode of the reflector unit the image is projected onto a first room surface, and in a second mode of the reflector unit the image is projected onto a second room surface, where the first and second room surfaces are non-coincident, and where a change from the first to the second mode is dependent on an input signal, 
         [0009]    a signal generator for generating the input signal indicative of a location of the patient. 
         [0010]    The reflector unit may comprise an input for receiving the input signal from the signal generator. 
         [0011]    Non-coincident first and second surfaces may be first and second areas on a wall which are distanced relative to each other, the first and second surfaces may be two walls of a room, e.g. non-parallel or parallel walls. Any of the first and second surfaces may comprise different or non-coincident areas of walls, the floor or the ceiling of the room. A room surface may also be a surface of a scanner located in the room. 
         [0012]    The reflector unit may be a separate component designed to be placed near the image projector, or the reflector unit may be a component of the image projector. However, advantageously the reflector unit is a separate component which may be used with any image projector. Since the image from the same projector can be projected onto different surfaces of the scanner room, the patient is able to see projected image even when the patient takes different positions within the scanner room. 
         [0013]    In an embodiment the image projection system further comprises a viewing device with one or two reflectors arranged to change the viewing path from a path between the patient and the first room surface to a path between the patient and the second room surface. 
         [0014]    Thus, the one or two reflectors may be arranged to change the optical path from patient to the projected image such that the patient can see the projected image when the reflector unit is in the second mode. In other words, the viewing direction of a patient may be redirected by the one or two reflectors to enable the patient to see the projected image when the reflector unit is in the second mode. 
         [0015]    In an embodiment the first surface is a surface adjacent to a patient entry of the scanner room and the second surface is a surface visible to a patient lying on a table of a scanner of the scanner room. 
         [0016]    In an embodiment the signal generator is a manually operable switch. E.g. the switch may be operable by the patient or clinical personnel. Accordingly, the patient is able to determine when he wishes to see the image after he is lying on the scanner table. 
         [0017]    In another embodiment the signal generator is a detector capable of detecting when the patient is in a particular position required for performing a scanning operation. Accordingly, the patient need not consider or take any actions for causing images to be visible when he is lying on the scanner table. 
         [0018]    In an embodiment the image projector is switchable between projecting 2D images and 3D images so that 2D images are projected when the reflector unit is in the first mode and 3D images are projected when the reflector is in the second mode, where projection of 3D images comprises projection of mutually displaced first and second images which are coded, such as color or polarization coded, so that the first and second images are viewable by the respective left and right eye of the patient. Advantageously, 3D images may enhance the viewing experience so that the anxiety of a patient may be reduced more in comparison with 2D images. 
         [0019]    In an embodiment the viewing device comprises coded viewing elements, such as color or polarization coded, for the respective left and right eye of the patient to enable viewing of the respective first and second images according to the embodiment of displaying 3D images. 
         [0020]    In an embodiment the image projector is configured to generate a border around the image. The appearance of the border may be set in correspondence of the appearance of the room lighting. When the border corresponds to the field of view enabled by the viewing device or the tunnel of the scanner, the viewing experience may not be negatively affected due to the reduced field of view since the border may create an impression that the field of view is not limited. 
         [0021]    In an embodiment the reflector unit is further switchable into a third mode where the image is projected onto a third surface which provides the patient entry to the scanner room. Therefore, when the patient leaves the scanner room he is presented with the image. This may be advantageous, since the final impression of the scan room will often determine the memory of the experience. For maximum patient comfort it is therefore important that the last viewed surface of the MR room is also part of the personally chosen room theme. 
         [0022]    An embodiment of the image projection system comprises a patient monitoring unit for detecting physiological parameters of the patient where the control unit has a processor for generating or modifying the image signal containing image information supplied to the image projector. Accordingly, the projected images may be set in dependence of the physiological parameters. Furthermore, if the heart rate increases calming music may be played. 
         [0023]    In an embodiment the image projection system according to claim comprises a surveillance system with a camera, where the system has image processing capabilities for detecting the presence of clinical personnel, and in dependence of a detected presence of clinical personnel changing a condition of the scanner room, such as the lighting intensity. 
         [0024]    A second aspect of the invention relates to a method for improving patient comfort in a scanner room for patient examination by projecting images onto a room surface by use of an image projector installed in the scanner room, where the method comprises 
         [0025]    generating a signal indicating a location of a patient within the scanner room, 
         [0026]    in dependence of the location given by the generated signal, projecting an image from the image projector onto a first surface if the signal indicates a first location and, projecting the image from the same image projector onto a second surface by redirecting the image using a reflector unit if the signal indicates a second location different from the first location, where the first and second room surfaces are non-coincident. 
         [0027]    In general the various aspects of the invention may be combined and coupled in any way possible within the scope of the invention. These and other aspects, features and/or advantages of the invention will be apparent from and elucidated with reference to the embodiments described hereinafter. 
         [0028]    In summary the invention relates to a method and a system for reducing anxiety of patients before and during e.g. MR scanning examinations. The method is based on displaying images on walls of the scanner room so that when the patient enters the scanner room, then an image is displayed on a wall visible to the patient, e.g. a wall adjacent to the entry door. When the patient is laying on the table of the scanner the projection of images is switched to another wall by reflecting the projected images using e.g. a mirror which is moved into the light rays emitted by an image projector. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0029]    Embodiments of the invention will be described, by way of example only, with reference to the drawings, in which 
           [0030]      FIG. 1  shows a scanner room with a scanner, 
           [0031]      FIG. 2  shows an image projection system with a reflector unit, 
           [0032]      FIG. 3  shows a viewing device for redirecting the viewing direction of a patient, 
           [0033]      FIG. 4  illustrates the limited field of view of a patient, 
           [0034]      FIG. 5  shows methods steps according to an embodiment of the invention. 
       
    
    
     DESCRIPTION OF EMBODIMENTS 
       [0035]      FIG. 1  shows a scanner room  100  with a scanner  101  such as an MR-scanner for scanning a patient (not shown) lying on the table  102 . The scanner room  100  has a patient entry  103  such as a door and window  104  which allows clinic personnel located outside the scanning room to watch the patient during the scanning process. 
         [0036]    An image projector  105  is installed in the scanner room for projecting an image onto a surface  106  of the room. The projected image content may be a still image or video images supplied to the image projector  105  as image data, e.g. from a computer. 
         [0037]    A reflector unit ( 202 , see  FIG. 2 ) is arranged in relation to the image projector  105  for redirecting the projected image into a first direction  112  different than the projection direction  111  of the image projector. Possibly, the image may be redirected into further directions different than the projection direction and the first direction. 
         [0038]    For example, the reflector unit  202  may be switchable into a third mode where the image is projected onto a wall surface which provides the patient entry  103  to the scanner room. 
         [0039]    Thus, in a first mode of the reflector unit the image is projected along the projection direction  111  onto a first room surface, e.g. surface  106  and in a second mode of the reflector the image is projected along the first direction  112  onto a second room surface. 
         [0040]    The first and second surfaces  106  and  107  may be walls of the room, the ceiling or floor of the room, or even the scanner itself where the projected image camouflages the presence of the scanner itself. The first and second surfaces  106  and  107  are different surfaces of the room, i.e. the first and second room surfaces are non-coincident, e.g. non-parallel or perpendicular, with respect to each other. 
         [0041]      FIG. 2  shows an image projection system  201  which comprises the reflector unit  202  and a control unit  203  connectable with an input  205  of the reflector unit  202  The input  205  is intended for receiving an input signal for controlling the actual mode of the reflector unit. 
         [0042]    The input signal may be generated by the control unit  203  or a signal generator  204  comprised by the control unit  203 . Thus, if the control unit  203  does not have other functions than generating the input signal for the reflection unit, the control unit may be referred to as the signal generator  204 . 
         [0043]    The reflector unit  202  may be a mirror  206  which can be positioned in at least first and second positions where, in the first position, the projection direction  111  of the projector is unchanged and in the second position the image forming light from the projector  105  is redirected into the first direction  112 . Thus, in the first mode of the reflector unit  202  the mirror  206  may be removed from the image forming light rays emitted by the projector  105  to let the light ray pass unobstructed. In the second mode the mirror  206  may be moved into the light rays to redirect the light ray into the first direction  112 . The angle of the mirror  206  relative to the projection direction  111  and the first direction is determined according to Snell&#39;s reflection law. 
         [0044]    Since the actual mode of the reflector unit  202  is dependent on the input signal received by the input  205 , the surface  106 ,  107  where the image is projected onto can be controlled by the reflector unit  202  so that a patient in the scanner room is able to see the image whether the patient enters the room via the entrance  103  or is lying on the table  102 . That is, the projection direction of the image forming light rays can be adjusted depending on the location of the patient. 
         [0045]    Since the patient is normally lying with his back on the table and with the eyes directed towards the ceiling it is difficult to see an image projected onto a wall such as surface  112  shown in  FIG. 1 . 
         [0046]    In order to enable the patient to conveniently view an image projected onto a wall a viewing device may be used to redirect the viewing direction from the patient&#39;s viewing direction towards the ceiling to a viewing direction towards one of the walls. 
         [0047]      FIG. 3  shows a viewing device  300  with one or two reflectors  301 , e.g. one reflector for each eye, arranged to redirect the viewing direction of a patient from a vertical direction  302  to a horizontal direction  303 . Thus, the viewing device enables the patient to see the projected image when the reflector unit is in the second mode. 
         [0048]    The viewing device may be in the form of a pair of glasses to be worn by the patient or a mirroring device which is fixed to the table  102  or the scanner  101  so that it is located in front of the eyes of the patient. 
         [0049]    The signal generator  204  in  FIG. 2  may be a switch operable by the patient or clinical personnel. For example, when the patient is lying down on the table  102 , the patient can change the mode of the mirror unit into the second mode so that the image from the image projector  105  is displayed on a surface which is visible to the patient. For example, in some scanners or in some scanner operations the ceiling may be visible to the patient and, therefore, the mirror unit may be operated to redirect the image to be displayed on the ceiling. However, often the scanner is constituted by a long narrow tunnel which surrounds the patient so that the only free viewing direction is along the tunnel, parallel with the floor. In this situation the image must be projected onto a wall surface adjacent one of the openings of the tunnel. 
         [0050]    Instead of a manually operable switch, the signal generator  105  may be a detector capable of detecting when the patient is in a particular position required for performing a scanning operation. The detector  105  may be a contact switch or a pressure sensor arranged with the table so that when the patient is lying down a detector is activated by the patient&#39;s weight. The change of the detector is signaled to the input  205  of the mirror unit  202  for causing a mode change into the second mode. Alternatively, the signal generator may be a camera system configured with image analyzing capabilities for detecting the location or orientation of the patient or simply for detecting whether a person is located on the table  102 . The signal generator  105  may also be a light ray detector arranged so that a passage of a light ray is obstructed when the patient is lying on the table  102 . 
         [0051]    In order to enhance the viewing experience by the user, 3D images may be projected onto the second room surface  107  instead of 2D when the reflector unit  105  is in the second mode. For that purpose, the image projector is switchable between projecting 2D images and 3D images so that 2D images are projected when the reflector unit is in the first mode and 3D images are projected when the reflector is in the second mode. Generation of 3D images where projection of 3D images comprise projection of relatively displaced first and second images which are coded, such as color or polarization coded, so that the first and second images are viewable by the respective left and right eye of the patient. 
         [0052]    In this 3D embodiment, the image projector  105  may be comprised by the image projection system  201  and the image projector  105  may have an input  215  connectable with the signal generator  204  or the reflector unit  202  for receiving the input signal generated by the signal generator  204 . The image projector may be configured to switch to 3D image projection when the input signal generated by the signal generator  204  for invoking a switch to the second mode of the reflector unit  205  is received by the input  215 . Thus, when the patient enters the scanner room  100  a 2D image is projected on the adjacent wall  106  and when the patient lies down on the table  102 , a 3D image is projected on the wall  107  which is visible for the patient. 
         [0053]    In order to perceive the projected 3D images as 3D images, the viewing device  300  may comprise coded viewing elements, such as color or polarization coded mirrors or glass plates, for the respective left and right eye of the patient. Thus, if the slightly displaced first and second images of the projected 3D images are polarization coded or color coded correspondingly with the coding of the viewing elements for the left and right eyes so that the left eye viewing element only allows transmission of the first images and the right eye viewing element only allows transmission of the second images, the first and second images will be perceived as a 3D image, i.e. an image containing depth information. Such 3D imaging techniques also referred to as stereoscopy is described in various text books. 
         [0054]      FIG. 4  illustrates the outer boundary  401  field of view which is visible for the patient lying on the table of the scanner. The field of view may be limited due to the viewing device  300  or due to the tunnel shaped scanner which surrounds the patient. In order to enhance the viewing experience a border  403  can be created which at least partly encircles the image  402 . The border may have a color and an intensity which matches the room lighting. In this way the patient experiences a more pleasant viewing of the image  402  since the border creates a gradual transition towards the outer boundary  401  of the field of view. Additionally, the border may include a zone wherein the image is gradually faded into the color of the room lighting, or the border  402  may contain other visual effects. 
         [0055]    The image data which are responsible for creating the border may be created by a processor for pre-processing the image that is to be projected by the projector  105 , for example by using the image data of the image  402  for creating a gradual washing out of the image  402 . The border  403  may also be created in response to an auxiliary input (not shown) of the image projector containing data information about the color and intensity of the room lighting. 
         [0056]    In order to further enhance the calming effect, the content of the projected images may be adapted to the patient&#39;s physiological conditions. For that purpose the image projection system may comprise a patient monitoring unit  298 , e.g. a camera connected to an image processor, for detecting physiological parameters such as heart rate and breathing of the patient. 
         [0057]    For example the heart rate can be determined from the camera image by analyzing images of the skin and breathing can be determined by comparing frames of the recorded images for determining motion frequency of the chest or the belly. 
         [0058]    The adaption of the images to the measured physiological conditions can be performed by a processor comprised by the control unit  203  for generating or modifying the image signal supplied to the image projector  105  in dependence of the detected physiological parameters. For example, a different image theme may be selected in dependence of the detected physiological parameters. 
         [0059]    In an embodiment the image projection system  201  comprises a surveillance system  299  with a camera, where the surveillance system has image processing capabilities—e.g. in the form algorithms processed by a processor for detecting faces—for detecting the presence of clinical personnel. If the presence of clinical personnel or any other person is detected, the surveillance system sends a signal to a processing unit comprised by the control unit  203 , or to other data processing systems capable of for example: 
         [0060]    switching on a spot light at a detected location of clinical personnel to ease work without disturbing the patient, 
         [0061]    lowering or muting a sound level of music when clinical personnel enters room and for achieving better patient communication, 
         [0062]    activating UV light if clinical personnel presents hands for disinfection, 
         [0063]    lowering the light level or shutter the image projector if staff is located in front of the projection surface, or 
         [0064]    muting or switching off the video when clinical personnel enters the scan room if they wish to limit their own exposure to annoying repetition of theme content. 
         [0065]    As another example, when the system comprises a camera, the camera image may be processed for detection of an area of the image where clinical personnel is located, and using this area for blocking an area of the projected image where the personnel is present, e.g. by decreasing the intensity of the projected image in that area. Alternatively, a silhouette image of the clinical personnel may be created in the projected image. The blocking of a part of the projected image or creation of a silhouette may be performed by adjusting the intensity and/or color of light emitted by e.g. by the LCD screen of the image projector, e.g. by making all those pixels where the staff is 0 and the rest 1 and multiple with the content image to be projected. 
         [0066]      FIG. 5  illustrates method steps according to an embodiment of the invention, where:
       step  501  comprises generating a signal indicating a location of a patient within the scanner room,       
 
         [0068]    step  502  comprises projecting an image from the image projector onto a first surface if the signal indicates a first location of the patient, and 
         [0069]    step  503  comprises projecting the image from the same image projector onto a second surface by redirecting the image using a reflector unit if the signal indicates a second location of the patient different from the first location. 
         [0070]    Other or additional method steps according to further embodiments may be included. 
         [0071]    While the invention has been illustrated and described in detail in the drawings and foregoing description, such illustration and description are to be considered illustrative or exemplary and not restrictive; the invention is not limited to the disclosed embodiments. Other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention, from a study of the drawings, the disclosure, and the appended claims. In the claims, the word “comprising” does not exclude other elements or steps, and the indefinite article “a” or “an” does not exclude a plurality. 
         [0072]    A single processor or other unit may fulfill the functions of several items recited in the claims. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage. 
         [0073]    Any reference signs in the claims should not be construed as limiting the scope.