Abstract:
An apparatus for prompting a patient includes a structure configured to be mounted to a patient support, an image source, and a screen coupled to the structure, wherein the screen is positionable relative to the image source. A method of prompting a patient that is being supported on a patient support includes adjusting a position of a screen relative to an image source, the screen having a surface, placing the screen in front of the patient such that the patient can see the surface, and using the screen to present a prompting signal to the patient.

Description:
RELATED APPLICATION DATA  
       [0001]     This application is related to U.S. patent application Ser. No. ______, entitled, “Patient Visual Instruction Techniques For Synchronizing Breathing With a Medical Procedure”, filed concurrently herewith, the entire disclosure of which is expressly incorporated by reference herein. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     1. Field of the Invention  
         [0003]     This invention relates generally to systems and methods for prompting patient, and more specifically, to systems and methods for prompting patient to control patient movement.  
         [0004]     2. Background of the Invention  
         [0005]     Computed tomography is an imaging technique that has been widely used in the medical field. In a procedure for computed tomography, an x-ray source and a detector apparatus are positioned on opposite sides of a portion of a patient under examination. The x-ray source generates and directs a x-ray beam towards the patient, while the detector apparatus measures the x-ray absorption at a plurality of transmission paths defined by the x-ray beam during the process. The detector apparatus produces a voltage proportional to the intensity of incident x-rays, and the voltage is read and digitized for subsequent processing in a computer. By taking thousands of readings from multiple angles around the patient, relatively massive amounts of data are thus accumulated. The accumulated data are then analyzed and processed for reconstruction of a matrix (visual or otherwise), which constitutes a depiction of a density function of the bodily section being examined. By considering one or more of such sections, a skilled diagnostician can often diagnose various bodily ailments such as tumors, blood clots, etc.  
         [0006]     Computed tomography has found its principal application to examination of bodily structures or the like which are in a relatively stationary condition. However, currently available computed tomographic apparatus may not be able to generate tomographic images with sufficient quality or accuracy due to physiological movement of a patient. For example, beating of a human heart and breathing have been known to cause degradation of quality in CT images.  
         [0007]     Degradation of quality of CT images due to patient&#39;s breathing is more difficult to address than that associated with heart motion. Patients&#39; breathing poses a unique problem to CT imaging that is different from heart motion. This is because the pattern and the period of a patient&#39;s breathing cycle is generally less consistent when compared to those of the patient&#39;s cardiac cycle. As such, while a particular phase of a cardiac cycle may be predicted with sufficient accuracy, a particular phase of a breathing cycle may not be as easily predicted or determined. Furthermore, there has been an increased desire to visualize organ motion by viewing a sequence of CT images as a movie sequence. However, collecting a large quantity of CT image data sufficient for forming a video while considering breathing motion is difficult to perform and may take a much longer time.  
         [0008]     For the foregoing, it would be desirable to prompt a patient to control the patient&#39;s breathing as CT image data are collected. The controlling can be in the form of 1) issuing periodic visual and audio commands to regularize the respiration motion so that a CT sequence can be formed as a function of the phase of breathing, or 2) using visual and audio commands to prompt the patient to hold breath at specific times and periods as required by the image acquisition process. Although visual signals have been used to prompt patients, use of visual prompting signals have been avoided in radiation procedures. This is because most image devices, such as a computer screen, is too large to fit within the bore of a CT machine. Even for those image devices that could fit within the bore of a CT machine, the image device will take up a lot of space within the bore. This may cause a patient who is confined within a gantry opening to feel uncomfortable—especially if the patient is claustrophobic. Also, electronics of an image device may interfere with a radiation field generated during a CT procedure.  
       SUMMARY OF THE INVENTION  
       [0009]     In accordance with some embodiments of the invention, an apparatus for prompting a patient includes a structure configured to be mounted to a patient support, an image source, and a screen coupled to the structure, wherein the screen is positionable relative to the image source and/or the patient.  
         [0010]     In accordance with other embodiments, an apparatus for displaying visual signal for prompting a patient includes a structure configured to be mounted to a patient support, and a screen having a first side, a second side, and a surface between the first and the second sides, wherein the first side is closer to the patient support than the second side when the structure is mounted to the patient support, and the screen is secured to the structure at the second side.  
         [0011]     In accordance with other embodiments of the invention, a method of prompting a patient that is being supported on a patient support includes adjusting a position of a screen relative to an image source, the screen having a surface, placing the screen in front of the patient such that the patient can see the surface, and using the screen to present a prompting signal to the patient.  
         [0012]     Other aspects and features of the invention will be evident from reading the following detailed description of the preferred embodiments, which are intended to illustrate, not limit, the invention.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0013]     The drawings illustrate the design and utility of preferred embodiments of the present invention, in which similar elements are referred to by common reference numerals. In order to better appreciate how advantages and objects of the present invention are obtained, a more particular description of the present invention briefly described above will be rendered by reference to specific embodiments thereof, which are illustrated in the accompanying drawings. Understanding that these drawings depict only typical embodiments of the invention and are not therefore to be considered limiting of its scope, the invention will be described and explained with additional specificity and detail through the use of the accompanying drawings in which:  
         [0014]      FIG. 1  illustrates a computed tomography system having a patient prompting device in accordance with some embodiments of the present invention;  
         [0015]      FIG. 2  illustrates a perspective view of the patient prompting device of  FIG. 1 ;  
         [0016]      FIG. 3  illustrates a side view of the patient prompting device of  FIG. 1 , showing the patient prompting device being used to prompt a patient;  
         [0017]      FIG. 4  illustrates a perspective view of a patient prompting device in accordance with other embodiments of the invention;  
         [0018]      FIG. 5  illustrates a side view of the patient prompting device of  FIG. 4 , showing the patient prompting device being used to prompt a patient; and  
         [0019]      FIG. 6  illustrates a perspective view of a patient prompting device in accordance with other embodiments of the invention.  
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0020]     Various embodiments of the present invention are described hereinafter with reference to the figures. It should be noted that the figures are not drawn to scale and elements of similar structures or functions are represented by like reference numerals throughout the figures. It should also be noted that the figures are only intended to facilitate the description of specific embodiments of the invention. They are not intended as an exhaustive description of the invention or as a limitation on the scope of the invention. In addition, an aspect described in conjunction with a particular embodiment of the present invention is not necessarily limited to that embodiment and can be practiced in any other embodiments of the present invention.  
         [0021]     Referring now to the drawings, in which similar or corresponding parts are identified with the same reference numeral,  FIG. 1  illustrates a computed tomography image acquisition system  10 , in which embodiments of the present invention can be employed. The system  10  includes a gantry  12  having an opening (or bore)  13 , a patient support  14  for supporting a patient  16 , and a control system  18  for controlling an operation of the gantry  12 . The system  10  also includes an x-ray source  20  that projects a beam of x-rays towards a detector  24  on an opposite side of the gantry  12  while the patient  16  is positioned at least partially between the x-ray source  20  and the detector  24 . The detector  24  has a plurality of sensor elements configured for sensing a x-ray that passes through the patient  16 . Each sensor element generates an electrical signal representative of an intensity of the x-ray beam as it passes through the patient  16 .  
         [0022]     In the illustrated embodiment, the control system  18  includes a processor  54 , such as a computer processor, coupled to a patient prompting device  100  and to a gantry rotation control  40 . The control system  18  may also include a monitor  56  for displaying data and an input device  58 , such as a keyboard or a mouse, for inputting data. During a scan to acquire x-ray projection data (i.e., CT image data), the gantry  12  rotates about the patient  16 . The rotation of the gantry  12  and the operation of the x-ray source  20  are controlled by the gantry rotation control  40 , which provides power and timing signals to the x-ray source  20  and controls a rotational speed and position of the gantry  12  based on signals received from the processor  54 . Although the control  40  is shown as a separate component from the gantry  12  and the processor  54 , in alternative embodiments, the control  40  can be a part of the gantry  12  or the processor  54 . The processor  54  is configured to send prompting signals to the patient prompting device  100  in a prescribed manner (e.g., in synchronization with a rotation of the gantry  12 ).  
         [0023]     The patient prompting device  100  is configured to provide visual signals to the patient  16  during a procedure, thereby instructing the patient  16  to perform certain task(s).  FIG. 2  shows the patient prompting device  100  in accordance with some embodiments of the invention. The patient prompting device  100  includes a screen  101  having a surface  102  between a first side  150  and a second side  152 , an image source  104 , and a structure  106  to which the screen  101  and the image source  104  are coupled. The screen  101  is preferably made from a non-metallic material and does not include circuitry for preventing interference with a radiation field. The screen  101  can be any object as long as it provides a surface. In the illustrated embodiments, the surface  102  is a mirror surface, and the image source  104  includes a flat panel screen (or a monitor screen). During use, the image source  104  receives image data from the processor  54  and displays an image  151  in response thereto. The image  151  is reflected by the mirror surface  102 , and the patient  16  can see the reflected image  151  by looking towards the mirror surface  102  ( FIG. 3 ). The image  151  displayed on the image source  104  is in reverse (or flipped) such that the patient  16  can see a reflection of the image  151  in a non-reverse (or intended) manner using the mirror surface  102 . In the illustrated embodiments, the image  151  provides visual signal to control the patient&#39;s breathing (e.g., by instructing the patient  16  to hold breath, to inhale, and/or to exhale). One application is to synchronize the patient breathing to a process being performed by a treatment or imaging device. For example, the patient breathing can be synchronized with a motion of the gantry  12  as the gantry  12  rotates around the patient  16  to collect image data, thereby ensuring that image data that correspond to a prescribed phase of a breathing cycle are obtained. However, in other embodiments, the image  151  can be configured to instruct the patient  16  to perform other task(s), such as, to relax, to move an arm or a leg, to respond to a question, etc.  
         [0024]     The above described configuration of the patient prompting device  100  is advantageous because it keeps the electronics of the image source  104  away from a radiation field generated by the x-ray source  20 , thereby preventing the electronics of the image source  104  from interfering a CT procedure. Also, it minimizes damage to the image source  104  due to X-ray radiation in a treatment machine. In addition, such configuration provides comfortable viewing of the image  151  because the patient  16  does not need to focus directly onto the image source  104 . Also, patients that are far sighted will not need to use reading glasses because reflection through mirror increases a length of the viewing path. Further, the low profile  160  of the prompting device  100  allows the device  100  itself to be placed inside the bore  13  of the CT gantry  12  (or other machines, such as a PET scanner).  
         [0025]     The position of the screen  101  can be adjusted relative to the image source  104  to accommodate different patients and/or different applications. In the illustrated embodiments, the structure  106  includes a first arm  110  for carrying the screen  101 , a second arm  112  for carrying the image source  104 , and connecting members  120 ,  118  for coupling the first arm  110  to the second arm  112 . Particularly, the screen  101  is rotatably coupled to an end of the first arm  110  via a shaft  130 , thereby allowing the screen  101  to rotate (as indicated by the arrows  146 ) relative to the first arm  110 . Coupling the screen  101  to the first arm  110  using the second side  152  (i.e., instead of the first side  150 ) of the screen  101  is advantageous because it allows the first arm  110  to be spaced further from a patient&#39;s head, thereby providing more level of comfort to the patient  16 . Similarly, the image source  104  is rotatably coupled to the second arm  112  via a shaft  132 , thereby allowing the image source  104  to rotate (as indicated by the arrows  148 ) relative to the second arm  112 . The connecting member  120  includes a slot  121  through which the first arm  110  can be inserted, and a knob  122  for securing the first arm  110  relative to the connecting member  120 . Such configuration allows the first arm  110  to be translated (in the directions  140 ), thereby adjusting a position of the screen  101 . The connecting member  120  is rotatably secured to the connecting member  118  via a shaft  124 , thereby allowing the first arm  110  to rotate relative to the second arm  112  (as indicated by the arrows  144 ). The connecting member  118  is sized to fit within a lumen  128  of the second arm  112 , and is slidable relative to the second arm  112  (as indicated by arrow  142 ) for adjusting a height of the screen  101 . In the illustrated embodiments, the connecting member  118  and the second arm  112  each has a non-circular cross section. However, in alternative embodiments, the connecting member  118  and the second arm  112  can each have a circular cross section, in which case, the connecting member  118  can be rotated about its axis relative to the second arm  112  to place the screen  101  at a desired position. A knob  126  is provided for securing the connecting member  118  relative to the second arm  112  after the connecting member  118  has been desirably positioned. In some embodiments, one or more of the components of the structure  106 , such as the first arm  110 , the surface, and the joining mechanism, can all be made from a non-metallic material, such as carbon graphite or a polymer, to minimize interference with a radiation field.  
         [0026]     The above described structure  106  is advantageous because it allows a position of the screen  101  to be adjusted in multiple directions. However, it should be noted that the structure  106  should not be limited to that described previously, and that the structure  106  can also have other shapes and configurations. For example, in alternative embodiments, the structure  106  can have more or less than two arms (e.g., arms  110 ,  112 ). Also, in other embodiments, if two or more arms are provided, one of the arms of the structure  106  can be configured to be moveable or non-moveable relative to another arm, and an orientation of one of the arms relative to another of the arms can be different from that described previously. In addition, in other embodiments, instead of, or in addition to, any of the type of movement characteristics of the screen  101  described previously, the structure  106  can have different number of arms connected by different types of connections to provide desired movement characteristic(s) for the screen  101  (relative to the image source  104  or to the patient support  14 ). Further, instead of arm(s) or elongated elements, the structure  106  carrying the screen  101  can include other structural elements, such as a block, a plate, a mechanical component, etc. As such, the structure  106  can be any object as long as it is capable of holding the screen  101  at a position relative to the image source  104 .  
         [0027]      FIG. 4  illustrates another patient prompting device  200  in accordance with other embodiments of the invention. Similar to the patient prompting device  100 , the patient prompting device  200  includes the screen  101  having the surface  102 , and the image source  104 . However, unlike the patient prompting device  100 , the structure  106  of the patient prompting device  200  does not include the first arm  110 . Instead, the structure  106  includes a bellow  202  for holding the screen  101  at a desired position relative to the image source  104 . The bellow  202  includes a first end  204  to which the screen  101  is secured, and a second end  206  that is inserted into the lumen  118  of the arm  112 . The bellow  202  includes a plurality of segments  208  that can be positioned relative to an adjacent segment  208 , thereby allowing the bellow  202  to be bent to a desired profile during use. Such connection is also known as a “goose neck” joint. During use, the image source  104  receives image data from the processor  54  and displays an image  151  in response thereto. The image  151  is reflected by the mirror surface  102 , and the patient can see a reflection of the image  151  by looking at the mirror surface  102  ( FIG. 5 ). In alternative embodiments, the structure  106  can include a second bellow for connecting the image source  102  to the arm  112 , to the first bellow  208 , or to the patient support  14  (in which case, the arm  112  is not required). Also, in other embodiments, instead of using a below, the structure  106  can include another type of bendable element, such as an elastic polymer shaft.  
         [0028]     Although the patient prompting device has been described as having a mirror surface, the scope of the invention should not be so limited. In other embodiments, the patient prompting device can include a non-mirror (e.g., a non-reflective) surface. In such cases, instead of the image source  104  being a flat panel or a screen, the image source  104  includes an image projector that projects image onto the surface  102 . Also, in other embodiments, the image source  104  can include fiber optics for transmitting image signals to a viewing surface. In such case, the screen  101  can be a component of a glasses or goggles, with the viewing surface  102  being an inside face of the glasses or goggles. Other types of image source can also be used in alternative embodiments.  
         [0029]     In other embodiments, the patient prompting device  100  or  200  can further include a connection mechanism for connecting the structure  106  to the patient support  14 . The connection mechanism can include, for examples, a clamp, a screw knob, or a pull-and-release type knob. In some cases, the connection mechanism can include one or more members connected to the structure  106  for mating with respective receiving members on the patient support  14 . In other embodiments, the patient prompting device  100  or  200  can further include the patient support  14 , in which case, the prompting device  100  or  200  can be fixedly secured to the patient support  14  (e.g., via a weld, a bolt, or a screw), or be detachably secured to the patient support  14 .  
         [0030]      FIG. 6  illustrates a patient prompting device  300  that is configured to be detachably secured to a patient support  320 . The patient prompting device  300  includes the screen  101 , the image source  104 , and the structure  106 , and is similar to the patient prompting device  100  described previously. The structure  106  includes a rod  302  (first arm) coupled to a support  304  (second arm), with the support  304  having an end  306  that is attached to a securing mechanism  308 . The securing mechanism  308  includes a plate  310 , members  311 ,  312  extending from the plate  310 , and securing elements  314 ,  316  located at respective ends of the members  311 ,  312 . The securing elements  314 ,  316  can be, for example, circular disks, or other types of fastening members. In the illustrated embodiments, the patient support  304  includes a plurality of recesses  322  on a first edge  330 , and a plurality of recesses  324  on a second edge  332 . The securing elements  314 ,  316  are configured to mate with the one of the recesses  322  and one of the recesses  324 , respectively, on both sides of the patient support  320 . The plurality of recesses  322 ,  324  allow a position of the patient prompting device  300  be adjusted relative to the support  320 . The securing mechanism  308  and the patient support  320 , and variations thereof, have been described in U.S. Pat. No. 5,806,116, the entire disclosure of which is expressly incorporated by reference herein.  
         [0031]     Also, in some embodiments, the patient prompting device  100  can include a processor, such as the processor  54 , for processing image signals/data. Further, in other embodiments, the patient prompting device  100  or  200  can further include one or more speakers for providing audio signal to the patient  16  in addition to the visual signal  50 . For example, the speaker(s) can be integrated speaker(s) that is part of the image source  104 . Alternatively, the speaker(s) can be separate speaker(s) that is secured to the structure  106  or to the patient support  14 . In addition, in other embodiments, the image source  104  can be configured to receive audio and/or video signals by one or more wireless connections. In such cases, the image source  104  includes its own power source and a wireless receiver for receiving signals from a transmitter.  
         [0032]     Although embodiments of the patient prompting device have been described as being used with the computed tomography image acquisition system  10 , in alternative embodiments, any of the embodiments of the patient prompting device described herein can be used to control patient motion in other types of radiation process. For examples, instead of a CT procedure, any of the above described patient prompting devices can be used in a laminar tomography procedure, a MRI procedure, a PET procedure, or other imaging procedures. Also, in other embodiments, instead of using the patient prompting device in image acquisition procedures, any of the above described patient prompting devices can be used in a treatment procedure, such as a radiation treatment procedure that requires a synchronization of a patient&#39;s movement to a treatment machine. In addition, in further embodiments, any of the embodiments of the patient prompting device described herein can be used in different applications, which may or may not require use of a radiation machine.  
         [0033]     Although particular embodiments of the present inventions have been shown and described, it will be understood that it is not intended to limit the present inventions to the preferred embodiments, and it will be obvious to those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the present inventions. For example, in other embodiments, instead of securing the image source  104  to the structure  106 , the image source  104  can be secured to the patient support  14 , or to another structure that is coupled to the patient support  14 . In such cases, the patient prompting device  100  or  200  does not include the image source  104 . Also, in other embodiments, the image source  104  is not limited to a single flat panel screen, a single monitor screen, or a single projector, and can include multiple image-providing devices (e.g., multiple flat panel screens, monitor screens, or projectors). For example, multiple image-providing devices can be used to provide 2-dimensional projection or holographic. The specification and drawings are, accordingly, to be regarded in an illustrative rather than restrictive sense. The present inventions are intended to cover alternatives, modifications, and equivalents, which may be included within the spirit and scope of the present inventions as defined by the claims.