System for positioning patients

territorially invention

The Invention relates to a system for positioning a patient according to the preamble of claim 1. In particular, the invention relates to a method and system for positioning patients that undergo a medical Treatment procedure to undergo.

State of technology

The accurate placement and positioning of the patient is critical, Although many types of medical treatments are performed. One category of medical treatments in which the exact Placing and verifying the position of the patient / patient's body parts is of particular importance is, is in the field of radiation therapy.

The Radiation therapy involves medical procedures that selectively certain areas of a human body, such as cancerous Tumors high doses of radiation exposes. The intent of the radiation therapy is to irradiate the target biological tissue, so that the harmful tissue destroyed becomes. To minimize damage to surrounding body tissue, using many conventional treatment methods "dose-fractionation" to the radiation dose planned in a supply series of treatment sessions, in which only a portion of the total planned dose is supplied. Healthy body tissues typically has a greater ability on, from damage to recover, which was caused by radiation exposure. splitting of the supplied radiation over many treatment sessions are healthy tissue the opportunity to recover from a radiation damage, thus the amount of permanent damage is reduced to healthy tissue while sufficient Radiation Exposure is maintained to destroy cancerous tissue.

The Effectiveness of the radiation treatment depends in large part on the ability from, to the body exactly the same position in the various radiation sessions irradiate. The goal is in every or all treatment sessions the patient in the same position relative to the radiation source to place. Inaccuracies in the positioning of the patient can Error in the radiation dose and / or the treatment site revealed resulting in an unpredictable disease relapse or damage to healthy cause tissue can. Maintaining the Linearbeschleuniger- / Radiation Source in a precise and repeatable position is normally not a problem. The problem arises when attempts are made at every radiation session the same body positioning to generate the patient again. In conventional medical Treatment systems is the accurate placement and verification of repeated treatment position on the human body significant problem in implementing dose fractionation regimens.

On Approach to control a patient positioning is, markings placing or tattoos at specific positions on the patient's skin. Some projected laser or light sources of predetermined locations Rays of light on the patient's body. To control the patient positioning, Move a therapist the position of the patient until the marks of the lines of light or the laser light sources are aligned. A significant Downside to this approach is that the accuracy and consistency positioning the patient to a high degree by the level of training Therapist for manual positioning of the patient depends. In addition, in heavier patients is possible that only the skin of the patient is moved to a precise position, without the body part to move, to be irradiated in the appropriate position. also manages this approach no efficient way, the positioning quality in the recorded patient record and reflect.

On Another approach to control a patient positioning is a Immobilisationsvorrichtung to use to the patient in a to maneuver certain position. A Immobilisationsvorrichtung is physically on the human body attached to prevent the patient from moving once a accurate positioning is achieved. A disadvantage of using a Immobilisationsvorrichtung's not that such devices for all Body Parts exist. Immobilisationsvorrichtungen are generally only for positioning the head and neck of the patient effectively. also a patient can in many known Immobilisationsvorrichtungen continues to a significant extent within the confines move the Immobilisationsvorrichtung. In addition, these devices can be extremely uncomfortable for be patient.

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On Positioning a patient with video cameras was in stereotactic Radiation surgery of the brain adopted in which the skull Patients will be positioned as a solid object. However, there are Disadvantages under when applying known positioning techniques Use of video cameras in non-fixed areas of the body. To the For such implementations are not suitable for the efficient To lead been the therapist through the steps for achieving a precise posture and Position must be given. Consequently occur therapists irritations, resulting from a long positioning process.

In order to there is a need for a system which relates to the above-described problems in the prior Technology oriented. There is a need for a system that accurately and consistent positioning of a patient for a medical treatment controls.

Summary the invention

The Invention provides a system for positioning a patient according the independent patent claim 1.

advantageous Other embodiments of the invention are in the dependent claims described.

Short description tHE dRAWINGS

The appended Drawings are included to provide a further understanding of the to provide invention and to together with the detailed description the embodiments to serve to explain the principles of the invention.

<figref idrefs="S34">1</figref> is a process flow diagram showing actions at a high level shows the in one embodiment, carried out the invention will.

<figref idrefs="S35">2</figref> shows a plurality of reference body locations, on a patient's body are arranged.

The <figref idrefs="S36">3a</figref> to <figref idrefs="S37">3e</figref> illustrate the application of an embodiment of the invention, to a relative and an absolute position of a correct patient.

<figref idrefs="S37">4</figref> shows a system for measuring and correcting a patient's position, according to a embodiment the invention.

<figref idrefs="S38">5</figref> illustrated a video display device and an example of a video image.

<figref idrefs="S38">6a</figref> is a side view of a camera used with the invention can be.

<figref idrefs="S38">6b</figref> is a front view of the camera <figref idrefs="S38">6a</figref>,

<figref idrefs="S39">7a</figref> is a sectional view of a retro-reflective Markers that can be used in the invention.

<figref idrefs="S39">7b</figref> is a perspective view of the retro-reflective marker from <figref idrefs="S39">7a</figref>,

<figref idrefs="S39">8th</figref> shows a device which can be used to the retro-reflective Marker from the <figref idrefs="S39">7a</figref> and <figref idrefs="S39">7b</figref> produce.

<figref idrefs="S40">9</figref> shows an embodiment a marker block.

<figref idrefs="S40">10</figref> shows an alternate marker block.

&lt;?page 4?&gt;

Detailed Description of Embodiments

Process Overview

<figref idrefs="S34">1</figref> is a process flow diagram showing actions at a high level, which in one embodiment, carried out the invention, will. The system of the invention starts with the measuring and storing reference coordinates of various body locations on a patient's body (<figref>102</figref>). Before feeding a radiation treatment at each treatment session should Patient to be positioned so that the current coordinates of these positions fit on the patient's body to the reference coordinates. The assumption that the radiation source to its original position is arranged, ensures that the patient in each session consistent and repeatable treatment at the same point receives.

If the patient is a treatment with different treatment sessions subjects, it is preferably on a treatment table, Treatment couch, or other type of patient support structure placed. For purposes of illustration the term should "treat table" in this document are used to refer to any supporting structure, which uses can be to take a patient. Initially, the patient is usually in an incorrect position relative to the reference coordinates. consistent encloses with the invention the initial Positioning action correcting the patient "posture" (<figref>104</figref>). "Posture" refers to the position of a or more parts of a patient's body parts relative to other the patient's body. In the process action <figref>104</figref> the measured posture the patient's body such re-positioned such that the relative positions of the patient's body parts match the relative positions of the reference coordinates. to this To achieve objective, the positioning system specific instructions ready to correct the relative position of the patient's body parts.

As soon as posture the patient has been corrected, should the measured body locations be in the correct positions in relation to the rest of the patient's body. However, the absolute coordinates of the patient's body positions to be wrong. If the patient is in the correct posture, then all body positions offset of the patient to the exact same deviation parameter value be when they are compared with the reference coordinates. In order to can the entire patient's body are moved as a unit to the right patient in the placing absolute coordinates to the reference coordinates match (<figref>106</figref>).

The Combination of actions to relative position error (<figref>104</figref>) and absolute position error (<figref>106</figref>to correct) and validate, significantly accelerates the time required for a patient Setting is needed before a treatment session. In addition, the invention allows during Treatment sessions more precise Detection and verification of patient positioning in real-time.

In an alternative embodiment, , after the relative and absolute positioning action was performed, an additional Positioning action will be carried out in relation to the internal organs of the patient. This additional Positioning action is performed to place the internal target volume set of external characteristics of the patient, and can be used in order precisely to position the internal organs of the patient for treatment. Each of the above process actions will be described in greater detail below will.

system of invention

In one embodiment covered the body positions, who are elected for measuring reference coordinates, general in two Categories. On the one hand one or more body positions be chosen to measure in the general vicinity of the body structure / of the institution, the / the undergoing treatment. On the other hand, other body positions chosen be, when a movement of such other body positions affects the orientation or arrangement of the body structure / of the institution, the / the undergoing treatment. For example, a Patient who undergoes treatment in the chest area, preferably have one or more reference positions, the chest area are measured, and possibly in other areas of the body, which may affect the position of the breast area, such as about the upper arm and the neck area. A patient who is a undergoing treatment in the prostate area, is preferably a or have a plurality of reference positions that are located in the hip area, and possibly in other areas of the body, that affect the movement of the prostate area, such as the upper leg areas.

&lt;?page 5?&gt;

In <figref idrefs="S35">2</figref> are the upper body and the upper arm of a patient <figref>202</figref> shown on the a treatment table <figref>204</figref> rests. For the purpose of illustration were a plurality of body positions <figref>206</figref>. <figref>208</figref>. <figref>210</figref> and <figref>212</figref> on the patient <figref>202</figref> marked. It is assumed that each body positions <figref>206</figref>. <figref>208</figref>. <figref>210</figref> and <figref>212</figref> to a body position corresponds, based on the orientation / positioning of a body organ effect, which is subjected to a treatment. Before Erstbehandlungssitzung is each of these body positions measured to reference coordinates in the Cartesian coordinate system provide. In one embodiment, the center of the system at the coordinates (0, 0, 0) is placed adopted. All measured body positions are given coordinates relative to the isocenter. For the purpose of explanation are the orientations of the X, Y and Z axes in <figref idrefs="S35">2</figref> shown. Other orientations may within the scope of the invention be used. For example, in an alternative embodiment, the orientation of the X, Y and Z axes with respect to the axial Movements or rotations of a scaffold to be defined, which the keeps radiation source or the linear accelerator.

table 1 provides examples of reference coordinates ready for the body positions <figref>206</figref>. <figref>208</figref>. <figref>210</figref> and <figref>212</figref> measured could be:

table 1 <img img-content="tb" img-format="tif" he="37" wi="129" file="00090001.tif" />

Referring on the <figref idrefs="S36">3a</figref>. <figref idrefs="S36">3b</figref>. <figref idrefs="S36">3c</figref> and <figref idrefs="S36">3d</figref> illustrate these figures the positioning process according to the invention. The patient<figref>202</figref> and the marked body locations <figref>206</figref>. <figref>208</figref>. <figref>210</figref> and <figref>212</figref> out <figref idrefs="S35">2</figref> were in <figref idrefs="S36">3a</figref> duplicated. This represents<figref idrefs="S36">3a</figref> the Reference position for a patient <figref>202</figref>, It is assumed that the reference coordinates for the body positions <figref>206</figref>. <figref>208</figref>. <figref>210</figref> and <figref>212</figref> in <figref idrefs="S36">3a</figref> as are continued in Table 1 below.

<figref idrefs="S36">3b</figref> illustrated an example of an initial Position and posture the patient <figref>202</figref> before the start of a treatment session. It is noted that in <figref idrefs="S36">3b</figref> the posture the patient is different from the reference posture of the patient <figref>202</figref> is, as described in <figref idrefs="S36">3a</figref> is shown. In other words are the relative positions between body locations <figref>206b</figref>. <figref>208b</figref>. <figref>210b</figref> and <figref>212b</figref>. in the <figref idrefs="S36">3b</figref> are shown, different the relative positions between their corresponding reference body positions <figref>206</figref>. <figref>208</figref>. <figref>210</figref> and <figref>212</figref> in <figref idrefs="S36">3A</figref>, In particular, the arm and shoulder of the patient (body positions <figref>206b</figref> and <figref>208b</figref>) in the wrong position relative to the remainder of the patient's body. In addition, the absolute position and / or orientation of the patient's body incorrectly. In particular, the patient <figref>202</figref> in <figref idrefs="S36">3b</figref> rotational offset from the exact reference position in <figref idrefs="S36">3a</figref> illustrated is.

Around posture to correct the patient, be at specific measured body positions the patient re-positioned, so that they are relatively measured in the correct position to the other body positions are.

The reference coordinate for body position <figref>206</figref> in <figref idrefs="S36">3a</figref> is (-18, 10, 5) and the reference coordinate for body position <figref>208</figref> is (-20, -5, -10). The means that the deviation between the reference coordinate for body position <figref>206</figref> and the reference coordinate for body position <figref>208</figref> in Relation to each of the Cartesian axes we be expressed can be: x-axis: -2, y-axis: -15, z-axis: -15

In one embodiment is the x-axis deviation between the two body locations by subtracting the x-coordinate for the body position <figref>206</figref> from the x-coordinate for body position <figref>208</figref> calculated. Similarly the y-axis deviation between the two body positions by subtracting the y-coordinate for the position of the body <figref>206</figref> from the y-coordinate for body position <figref>208</figref> calculated. The z-axis deviation between the two body positions is calculated by subtracting the z-coordinate for the position of the body <figref>206</figref> from the z coordinate for body position <figref>208</figref> calculated.

&lt;?page 6?&gt;

Around the relative positioning between body positions <figref>206b</figref> and <figref>208b</figref> to correct, the relative difference between these two should body positions be manipulated so that it fits to the deviation, which for its corresponding Reference coordinates was measured. For example, if the patient<figref>202</figref> in <figref idrefs="S36">3b</figref> not correct was positioned so that the position of the body <figref>206b</figref> to the coordinate (0, 0, 0) has been moved toward the can body position <figref>208b</figref> to the coordinate (-2, -15, -15) toward be moved to the same relative position between these two body positions to restore, as for their corresponding reference coordinates have been determined. The same relative position, by moving the position of the body <figref>206b</figref> instead body position <figref>208b</figref> achieved be, as long as the deviation between the two body locations is corrected to the reference deviation. Alternatively, both body positions while this process can be moved as long as the end result is that the relative difference between the two body positions with the relative Deviation of the corresponding reference coordinates matches.

Similarly, the deviation between the reference coordinate for body position <figref>210</figref> (0, 10, 2) and reference coordinate for body position <figref>212</figref> (-10, 0, words 4) are as: x-axis: -10, y-axis: -10, z axis: -2

In order to, when the body position <figref>210b</figref> in <figref idrefs="S36">3b</figref> to Coordinate (0, 0, 0) is moved toward, then the body position <figref>212b</figref> to Coordinate (-10, -10, -2) toward be moved to maintain the same relative positioning, the corresponding measured and between their reference coordinates was established.

In one embodiment provides the positioning system specific instructions ready to the positioning of the body parts to correct the patient. There are a number of techniques, a positioning plan or recipe positioning provide, the posture to correct the patient. In one approach, the collection of marked body locations mathematically translated as a solid object, that they with the Collection of reference positions overlap. In other words, the arrangement of data for the entire collection of be labeled body positions mathematically the arrangement data for placed the collection of reference positions. Subsequently the placement data for the entire collection of marked body locations logically a single unit moved to try, a best overall match between the collection of marked body locations and the collection finding of reference positions. This can be either through a center a mass-translation or by a matching of many so labeled body positions as possible be done with reference positions. The remaining error marked between the position of each non-matching body position and their corresponding reference position defines the posture error, of this body position is associated. In this way the system can specific instructions providing that precise lead them like any body part to be moved to the body posture to an acceptable level to correct. These specific instructions can from a therapist be used to posture corrections perform.

to Illustration is the collection of marked body locations <figref>206b</figref>. <figref>208b</figref>. <figref>210b</figref> and <figref>212b</figref> in <figref idrefs="S36">3b</figref>, If the entire collection of marked body locations in <figref idrefs="S36">3b</figref> mathematically translated as a solid object was to be in the collection of reference positions <figref idrefs="S36">3a</figref> to overlap, then could the Point of the best lap be where the body position <figref>210b</figref> on a line with the reference position <figref>210</figref> and the position of the body <figref>212b</figref> on a line with the reference position <figref>212</figref> lies. The misalignment between the relative positions of the body positions <figref>206b</figref> and <figref>208b</figref> and the reference position <figref>206</figref> and <figref>208</figref> would then as posture error defined.

In a display image, the positioning visual instructions present, to the posture error to correct. instructions arrow<figref>213</figref> in <figref idrefs="S36">3b</figref> is an example of a visual statement that presents a therapist can be to a specific pictorial guide for correcting the posture error provide. The instruction arrow<figref>213</figref> can or vaguely about the image of the patient to be placed to the correction of the posture error to facilitate. <figref idrefs="S37">3e</figref> shows an enlarged view the instruction arrow <figref>213</figref> out <figref idrefs="S36">3b</figref>,

As shown, provides the instruction arrow <figref>213</figref> a specific guide for the Direction of correction and for the required amount of correction ready.

In an alternative embodiment, the posture correction by selecting a single measured body position accomplished as a main reference point. Any other measured Körperpo&lt;?page 7?&gt;sition is positioned so that its position relative to the main reference point with the relative deviation corresponds, the observed between the same two points on the reference coordinate and was measured. Alternatively, the posture correction in a Chain Approach be accomplished, in which a first measured body position is a second measured body position re-positioned relative. Once the first and second measured body position accurately relative were positioned to each other, a third measured body position positioned relative to the second measured body position. Once the second and third measured body position accurately relative were positioned to each other, a fourth measured body position positioned relative to the third measured body position. This is continued until all the remaining measured body positions accurately positioned were.

<figref idrefs="S36">3c</figref> shows patient <figref>202</figref>Once the posture errors <figref idrefs="S36">3b</figref> corrections were. It can be perceived that, once the posture has been corrected of the patient, the relative deviations of all measured body positions match the relative deviations, noted for its were measured corresponding reference coordinates and determined. This determines the relative positioning between body positions <figref>206c</figref>. <figref>208c</figref>. <figref>210c</figref> and <figref>212c</figref> in <figref idrefs="S36">3c</figref> With the relative positioning between the reference coordinates for the body positions <figref>206</figref>. <figref>208</figref>. <figref>210</figref> and <figref>212</figref> in <figref idrefs="S36">3a</figref> agreement. Especially was the upper arm and shoulder of the patient <figref>202</figref> (Body positions <figref>206c</figref> and <figref>208c</figref>) in the same position relative to the rest of the body re-positioned, as for the reference coordinates was measured and determined.

As soon as a posture correction performed and verification was, the absolute position of the patient's body must be corrected and / or verified will. Even if the body posture have been corrected, it is possible to that the coordinates of the measured body positions not with the may coincide absolute coordinates of the reference coordinate. in the example of <figref idrefs="S36">3c</figref> , although the posture of Patient has been corrected, the absolute position of the patient <figref>202</figref> not correct because the patient's body rotational is offset from the reference position in <figref idrefs="S36">3a</figref> shown is. However, it should, because the posture correction already done was, at any part of the patient's body be offset by exactly the same deviation parameters. In order to can, rather than individual parts of the patient maneuver to have to, In order to achieve an accurate positioning, the entire patient's body as a unit be maneuvered in the exact position to the absolute conform position of the reference coordinates.

in the example in <figref idrefs="S36">3c</figref> the entire patient's body in by the arrow <figref>302</figref> marked direction rotates. In one embodiment, If this movement of the entire patient's body by moving the Support structure causes, on which the patient rests, for example of the treatment table. <figref idrefs="S36">3d</figref> shows a patient <figref>202</figref>Once the entire patient's body re-positioned has been. In<figref idrefs="S36">3d</figref> were the absolute coordinates body positions <figref>206d</figref>. <figref>208d</figref>. <figref>210d</figref> and <figref>212d</figref> so positioned to coincide with their corresponding reference coordinates.

According to a embodiment an additional Positioning action with respect to the inner regions of the treatment performed patients will. In certain circumstances, can the internal body structure or the organ to be treated, from a previous shift arrangement / position, even though the external body positions were placed so that they coincide with the reference coordinates.

On first method to perform internal positioning measurements and corrections comprises, the use of an imaging system such as an X-ray imaging system on which specific internal characteristic points within the patient's body can detect. Such characteristic points can in particular Bone structures close be the organ to be treated. The imaging system is used, to reference positions for the body structures measure, which are selected as characteristic points. At a following treatment session, the imaging system used to make these positions of the same characteristic structures measure within the patient. The patient undergoes fine Body settings until the characteristic structures of the previous measured Reference positions are positioned.

On second method to inner position measurements and corrections perform, includes using an imaging system that directly the Organs or body structures may map to be subjected to a treatment, such as Ultrasound or MRI imaging systems. The imaging system measures a reference position and orientation the organ or body structure, the treatment is subjected. For example, if an ultrasound imaging system is used, then the system, the position of an organ or a body structure detecting with respect to the ultrasound probe. The ex&lt;?page 8?&gt;Act position the ultrasound probe is measured with respect to the rest of the system. One or more markers (described in more detail below) can be attached to the ultrasound probe to determine its position. Based on the position of the ultrasound probe, the position of the internal organ or body structure are calculated relative to the remainder of the system. In a following Treatment session undergoes the patient fine body settings, to organs or body structures to place in the original reference position and orientation.

<figref idrefs="S37">4</figref> shows a Patientenmessungs- and Positioning <figref>400</figref> according to a embodiment the invention. In<figref idrefs="S37">4</figref> is a patient <figref>402</figref> shown, by a treatment table <figref>404</figref> will be carried. A plurality markers <figref>406</figref> (Preferably back-reflective or reflective Marker) are at a plurality of body locations on the patient <figref>402</figref> fixed. One method of particular body positions select, via which back-reflective marker <figref>406</figref> are fixed, was described above. In a embodiment , each back-reflective marker <figref>406</figref> reflective material on the light either can reflect in the visible or non-visible wavelength range. Two or more cameras <figref>408</figref> are positioned to direct light to detect and record which of the markers <figref>406</figref> reflected becomes. The output of the cameras<figref>408</figref> is a computer <figref>410</figref> sent or a different type of processing unit, the ability to has to take video images. According to a particular embodiment , the computer <figref>410</figref> an Intel Pentium^TM-based processor on, on the Microsoft Windows NT^TM running, and has a video frame grabber card on which a multi-channel device is and a separate channel for each camera <figref>408</figref> Has, which is used in the system.

at an operation projecting one or more illumination sources (Which in the preferred embodiment Infrared sources) light on the patient <figref>402</figref> on the treatment table <figref>404</figref>, The generated light is of the retro-reflective markers <figref>406</figref> reflected, whereby the position of these retro-reflective markers <figref>406</figref> indicated will. The cameras<figref>408</figref>Which the patient <figref>402</figref> are directed, capture and detect the reflected light from the retro-reflective markers <figref>406</figref>, Each camera <figref>408</figref> generates video images of the position retro-reflective marker <figref>406</figref> show in their video frames. The video images generated be further processed to the computer <figref>410</figref> Posted.

Of the computer <figref>410</figref> receives the video images from the cameras <figref>408</figref>, Generally show the recorded video images from each camera <figref>408</figref> just the position of the retro-reflective marker <figref>406</figref> relative to the particular camera <figref>408</figref>. produces the image. The two sets of images of the respective cameras <figref>408</figref> be added, are the computer <figref>410</figref> used to determine the absolute coordinates of each retro-reflective markers <figref>406</figref> to triangulate. In a first treatment session, the reference coordinates of each retro-reflective marker <figref>406</figref> measured and in the computer <figref>410</figref> stored. subsequently can with any other treatment session the system <figref>400</figref> in Real-time the absolute coordinates of each retro-reflective marker <figref>406</figref> measure and in real time the coordinates of the marker <figref>406</figref> with the Compare stored reference coordinates. Although only two cameras<figref>408</figref> in <figref idrefs="S37">4</figref> shown are any number of cameras <figref>408</figref> in the system <figref>400</figref> used be to video images of the patient <figref>402</figref> and the retro-reflective brand <figref>406</figref> take. Information regarding the Location and orientation of each camera <figref>408</figref> will the computer <figref>410</figref> provided to the triangulation to enable.

A possible Inefficiency in allocating the retro-reflective markers <figref>406</figref> is, that the marker may appear in the video frame somewhere, and all the pixels of the video frame can be examined to the arrangement of the retro-reflective marker <figref>406</figref> to determine. Thus, in one embodiment the initial Determining the arrangement of the retro-reflective marker <figref>406</figref> an examination of all the pixels in the Video frame. If the video frame having 640 × 480 pixels, then all 307200 (640 × 480) Pixels initially examined to the arrangement of the Marker <figref>406</figref> to find.

For a real-time mapping the retro-reflective marker <figref>406</figref> could an examining every image element for every video frame to the Arrangement of markers <figref>406</figref> to determine in real time, consume significant amount of system resources. Therefore, in one embodiment the real-time assignment of the retro-reflective marker <figref>406</figref> by processing a small region of the video frame allows are referred to herein as "partitioning grid", the estimate based on a the arrangement of the previously identified marker <figref>406</figref> in placed the video frame. The foregoing specific arrangement of a Markers <figref>406</figref> is used to an initial Search frame (ie, the mapping grid) for that same marker in to define real time. The assignment lattice is a relatively small Area of ​​the video frame, the at the previous location of the marker <figref>406</figref> centered is. The allocation grid is only extended,&lt;?page 9?&gt;if it is not the new location of the marker <figref>406</figref> contains. As an example, the to consider the situation if the previous detected position a specific marker picture element (50, 50) in a video frame. If the mapping grid on a 50 × 50 area of ​​the video frame is limited, then the mapping grid is in this example contain image elements grouped within the range are represented by the coordinates (25, 50), (75, 50), (50, 25) and (50, 75) is defined. The other areas of the video frame only searched when the marker <figref>406</figref> not within this Assignment lattice is found.

at each treatment session, the retro-reflective markers <figref>406</figref> at the same predetermined positions on the body of the patient <figref>402</figref> fixed. At the beginning of each treatment session, the coordinates for each retro-reflective markers <figref>406</figref> by the computer <figref>410</figref> triangulated. If the relative or absolute positioning of the retro-reflective marker <figref>406</figref> is false, then the computer generates specific Information that can be used to correct these errors. This real-time feedback in terms of the position of the rear reflective markers <figref>406</figref> can while his treatment session provided so that any position error, the while the treatment occurs can be detected and corrected.

In one embodiment the posture correction performed manually by a therapist or assistant. Of the computer <figref>410</figref> provides instructions on a video display device <figref>412</figref> regarding the specific movement of the measured body position ready to use be to determine the exact relative positioning of the patient's body to justify. For example, the video display device <figref>412</figref> informations in terms of the exact x, y and z axis settings show that in certain body positions needed are to posture error to correct. Alternatively, the treatment table<figref>404</figref> Body manipulation fixations comprise, by the computer <figref>410</figref> being controlled. In this embodiment, are the computerized fixations by the computer <figref>410</figref> emotional, so that the posture the patient <figref>402</figref> is automatically adjusted to the accurate relative positioning of the various body positions to justify.

As soon as the exact posture is established, the patient is <figref>402</figref> in the exact absolute shifted position. In one embodiment, the treatment table<figref>404</figref> a movable on the structure, the position and the rotation concerning can be adjusted. The entire body of the patient<figref>402</figref> becomes as a single unit by the treatment table <figref>404</figref> postponed In order to achieve the exact absolute coordinates and to the Reference coordinates correspond most exactly. In the preferred embodiment the movement of the treatment table <figref>404</figref> by the computer <figref>410</figref> controlled. Once the posture Settings accomplished are, the computer controls the movement of the treatment table <figref>404</figref> so, he patient <figref>402</figref> in the exact absolute position brings. In an alternative embodiment, the treatment table is<figref>404</figref> manually maneuvered by an assistant or a therapist, around the patient <figref>402</figref> in the correct absolute position to place. A video display device<figref>412</figref> provides Information with respect to the precise movement of the treatment table <figref>404</figref> ready, the effect the position correction. Fine-tune the patient's position, to correct position errors of internal organs or body structures, can also by moving the treatment table <figref>404</figref> be performed.

In one embodiment the movement by the computer <figref>410</figref> controlled. Referring on <figref idrefs="S38">5</figref> represents in one embodiment, the system <figref>400</figref> on video image <figref>502</figref> the patient (or certain body positions on the patient) on a video display device <figref>412</figref> ready. The video image is provided to a therapist or a Assistant in positioning the patient to assist. Within of the video image <figref>502</figref> are reference positions of the retro-reflective Marker as illuminated dots <figref>504</figref> displayed. The real-time image and the position <figref>508</figref> the retro-reflective marker also on the video display device <figref>412</figref> as illuminated Points <figref>508</figref> displayed (in <figref idrefs="S38">5</figref> represented as "x" marks) which are preferably a different shape and color as the images of the reference coordinates <figref>504</figref> have. The real-time image <figref>510</figref> the patient can also be displayed will. In one embodiment, can the reference image <figref>506</figref> the patient also on the Video display device <figref>412</figref> are displayed. The reference image<figref>506</figref> can are switched to the real-time image <figref>510</figref> the patient replace, so that only a single image of the patient at any Time is displayed even when both the reference and the real-time positions the markers are displayed simultaneously.

alternative can the reference image <figref>506</figref> over or super positioned over the Real Time <figref>510</figref> of the patient are placed so that both sets of Images of the patient are displayed at the same time. The real-time nature the image display allows any movement of the markers or certain body positions on the patient directly on the video display device <figref>412</figref> display. Thus, the image on the Vi&lt;?page 10?&gt;deo crystal display device <figref>412</figref> used are to assist in the correction of posture and absolute Position error to assist. For example, allows the simultaneous display of both the reference and the real-time positions of the markers a therapist to visually determine adjustments needed to the two sets align marker images and correct position errors. also allows Display of the reference and real-time images of the patient a Therapist to visually determine adjustments that are needed, to posture error to correct.

The <figref idrefs="S38">6a</figref> and <figref idrefs="S38">6b</figref> show an embodiment a camera <figref>408</figref>Used in the invention can. The camera<figref>408</figref> is a charge coupled device (CCD) camera having one or more photoelectric cathodes and one or more CCD devices. A CCD device is a semiconductor device including a charge in local can store areas and which have appropriate control signals can transfer this charge to a readout point. When light photons focused on the scene to be imaged on the photoelectric cathodes are, electrons are released proportional to the light intensity, which has included the camera. The electrons are in charge stores retained, which are located within the CCD device. The distribution of captured electrons in the charge stores represents the image that has been captured by the camera. The CCD device transfers this Electrons to an analog-to-digital converter. The output the analog-to-digital converter is sent to the computer <figref>410</figref> Posted, to process the video image and the positions of the retro-reflective calculate marker. According to a embodiment of the invention is the camera <figref>408</figref> a monochrome CCD camera with an RS-170 output and 640 × 480 pixel resolution. Alternatively, the camera <figref>408</figref> a CCD camera with CCIR output and 756 × 567 pixel resolution exhibit.

In a specific embodiment, of the invention is an infrared illuminator <figref>602</figref> ( "IR illuminator") together with the camera <figref>408</figref> arranged. The IR illuminator<figref>602</figref> generated one or more beams of infrared light, the same in the Direction as the camera <figref>408</figref> directed. The IR illuminator<figref>602</figref> has a surface , which as a ring around the lens <figref>606</figref> of the camera body <figref>608</figref> arranged is. The surface IR illuminator <figref>602</figref> includes a plurality of individual LED elements <figref>604</figref> for generating infrared light. The LED elements<figref>604</figref> are in a spiral Pattern on the IR illuminator <figref>602</figref> arranged. Infrared filter, the part of the camera <figref>408</figref> can be removed or except Function set to the sensitivity of the camera to infrared improve lighting.

The Positions and orientations of the cameras <figref>408</figref> should be calibrated to ensure that the absolute coordinates the retro-reflective marker <figref>406</figref> can be accurately calculated. To Camera<figref>408</figref> to calibrate, is a reference target on the treatment table in a specific arrangement placed. The reference target includes a Set of well-defined target elements in a known height and orientation. The Data obtained by the cameras <figref>408</figref> added for the reference target will be used to precisely perform position and orientation calibrations. More information regarding the calibration of multiple cameras in a video / optical The illustration system can in "Close-range Camera Calibration", Photogrammetric Engineering, 37, 855-866 (1971) and The Handbook of Non-Topographic Photogrammetry-, Second Edition, American Society of Photogrammetry and Remote Sensing (1989), are found, incorporated herein via reference both are.

The <figref idrefs="S39">7a</figref> and <figref idrefs="S39">7b</figref> show an embodiment a retro-reflective markers <figref>700</figref>. which can be used in the invention. A rear-reflective marker <figref>700</figref> has increased reflecting surface <figref>702</figref> to the Reflect on light. The increased reflective surface<figref>702</figref> has preferably an approximately semi-spherical Shape so that light regardless can be reflected on the incident angle of the light source. A flat surface <figref>704</figref> surrounds the increased reflective surface. The underside of the flat surface <figref>704</figref> provides an attachment portion for attaching the retro-reflective marker <figref>700</figref> at specific locations on a patient's body ready. According to a embodiment has a back-reflective marker <figref>406</figref> a back-reflecting material 3M # 7610WS on which is available from 3M Corporation. In one embodiment, , the back-reflective marker <figref>700</figref> a diameter of about 0.5 cm and a height of the highest point the increased reflective surface <figref>702</figref> from about 0.1 cm.

<figref idrefs="S39">8th</figref> shows a device <figref>802</figref>That can be employed to the retro-reflective marker <figref>700</figref> produce. The device<figref>802</figref> has a base region <figref>804</figref> with a fixed thereto elastic ring <figref>806</figref> on. The elastic ring<figref>806</figref> is at a Floor-casting <figref>808</figref> fastened with a bulge that by itself its center of stretches. An actuating lever<figref>810</figref> can actuated are to the upper portion <figref>812</figref> along the support rods <figref>814</figref> to move. The upper portion<figref>812</figref> Adjusted spring has a top casting <figref>814</figref> on. The upper casting<figref>814</figref> is with a semi-spherical Recess formed on its underside. is Upon actuation one piece of the retro-reflective Material on the lower casting <figref>808</figref> placed. Of the&lt;?page 11?&gt;actuating lever <figref>810</figref> becomes actuated around the upper portion <figref>812</figref> toward the base region <figref>804</figref> to move. The back-reflective Material is compressed and between the lower casting <figref>808</figref> and the upper casting <figref>814</figref> shaped. The upper casting <figref>814</figref> forms the upper exterior of the back-reflective Material in a semi-spherical Form.

In an alternative embodiment, has a marker <figref>406</figref> a marker block having one or more Reference positions on its surface. Each reference position on the marker block preferably comprises a retro-reflective or reflective material which through an optical imaging device such as a camera <figref>408</figref> is detectable.

<figref idrefs="S40">9</figref> shows an embodiment a marker block <figref>900</figref> having a cylindrical shape with more reference positions, the back-reflective elements <figref>902</figref> show and on its surface are arranged. The marker block<figref>900</figref> , as a solid Block (eg from polystyrene) may be formed. Blocks, and in this type Manner are prepared, can be reused repeatedly, even in several patients. The retro-reflective elements <figref>902</figref> can be formed from the same material that is used to back-reflective markers <figref>406</figref> of the <figref idrefs="S39">7a</figref> and <figref idrefs="S39">7b</figref> to form. The marker block is preferably formed of a material, that is lightweight enough to not obstruct normal breathing of the patient obstructing.

On Advantage of using a marker block such as the block marker <figref>900</figref> is, it with an a priori knowledge of the relative positions of Reference positions / retro-reflective elements <figref>902</figref> on the marker block <figref>900</figref> possible is, all 6 degrees of freedom of the marker block from a single Camera view to determine out. In other words, only a single camera required to the absolute coordinates of a marker block <figref>900</figref> derive. This arises because the relative positioning between the retro-reflective elements <figref>902</figref> on the surface the marker block <figref>900</figref> are known, and the absolute coordinates and view orientations of the camera <figref>408</figref> also known are. The by the camera<figref>408</figref> detected image of the marker block <figref>900</figref> indicated positioning the visible reference locations / retro-reflective elements <figref>902</figref> relative to the view orientation of the camera. Because the actual relative positions between the retro-reflective elements <figref>502</figref> known are able the detected relative coordinates of the visible retro-reflective elements <figref>902</figref> from used the camera image to the absolute coordinates of marker block <figref>900</figref> derive.

On Marker block can be formed in any shape or size as long as the size, distances and the positioning of the reference locations are configured to that a camera or other optical imaging apparatus can absorb and generate an image that accurately positioning shows at least two / three or more of the reference positions. example shows <figref idrefs="S40">10</figref> an alternate marker block <figref>1000</figref> With a hemispheric Form containing a plurality of retro-reflective elements <figref>1002</figref> having that attached to their surface are.

Of the Marker block can be formed into shapes that at certain parts of the body fit. For example, Molds or impressions, that match specific locations on the body, as a marker block be used. Marker blocks, which are shaped to fit to particular areas of the body, allowing the repeated placing the marker blocks at particular positions on the patient. Alternatively, the marker blocks be designed so that they fit certain fixations, attached to a patient's body be attached. For example, a marker block within wells be constructed or notches which allow him to a pair of glasses to be attached. In yet another embodiment, the fixations integrally with marker blocks formed having reflective or retro-reflective markers on itself.

A alternative embodiment the marker block comprises only a single reference position / a reflective Element on its surface on. This embodiment of the marker block is used instead of a retro-reflective marker <figref>406</figref> used at certain positions on a patient's body with an optical imaging device to detect.

In a previous specification was the invention with reference to specific embodiments it described. However, it is apparent that various Modifications and alterations done it can be, without departing from the scope of the invention as appended in the claims is defined. For example,, rather than using reflective or retro-reflective Markers, the coordinates for different body positions on a patient by generating images of certain characteristic Points on a patient's body are obtained. Accordingly, the specification and drawings rather in an illustrative than in a restrictive &lt;?page 12?&gt;to see sense.