DE20009909U1 - Positioning aid for the tomographic functional examination of the lumbar spine - Google Patents

Description

Applicant: Stuttgart, 23.05.2000

P7549GM B/ai Dr. Rolf Schindler
Wiesengasse 14

D-97424 Schweinfurt <

Representative:

Kohler Schmid + Partner
Ruppmannstrasse 27

D-70565 Stuttgart

Positioning aid for tomographic functional examination of the lumbar spine

The invention relates to a positioning aid for tomographic functional examination of vertebrates, in particular humans, with a base plate extended along a z-direction parallel to the tomograph axis, which is preferably positively connected to a movable patient bed of a tomography apparatus, wherein a shoulder plate is attached to the base plate in the thorax region of the patient to be examined, which enables a steadily increasing positioning of the thorax region of the patient to be examined in the direction of the head relative to the base plate.

Such a positioning aid for tomographic functional examination of the cervical spine is known from the article by J. Tacke et al. "A continuously variable pneumatic movement device for dynamic MRI of the cervical spine" in the journal Fortschr Röntgenstr 171 (1999) 249-253.

In the daily practice of tomography, especially in magnetic resonance imaging (MRI) _1, examinations of the spine take up a lot of space because the diagnostic potential is much greater than with conventional (X-ray) procedures due to the better differentiation ability for different types of tissue. But in principle such examinations can also be carried out in computer tomography (CT).

The development of new pulse sequences in MRI made it possible, depending on the diagnostic question, to delineate the spinal canal with its cerebrospinal fluid, bones, intervertebral discs, ligaments or even vessels in high resolution from each other and from the surrounding tissue without contrast medium.

Modern digital image processing methods in conjunction with fast computers are also able to combine the individual data sets into a complete anatomical image and also display it in three dimensions - for example for surgical planning. Additional sectional planes can also be displayed subsequently without additional examinations.

Radiologists still consider one of the greatest disadvantages of MR imaging in spinal diagnostics to be that effective examinations in different functional positions - as is common in conventional myelography, for example - are practically impossible.

Also due to the relative narrowness of the magnets used in diagnostics, many radiologists estimate the achievable range of motion to be too small to gain additional information through functional examinations.

Open MRI devices are occasionally used in this context. However, such systems are not available to most radiologists. High-resolution images are also only possible to a very limited extent due to the lower magnetic field strengths.

In recent years, many attempts have been described in the literature to achieve individual functional positions using more or less experimental positioning aids. These attempts have at least shown that certain functional positions are possible and sufficient to answer specific questions that were previously not accessible to MRI and that are often difficult to clarify using other methods - if at all.

However, all of these positioning aids - if they are commercially available at all - are of little use for routine diagnostics, because the wide range of possible movements of the entire spine requires a large number of individual devices that then have to be installed or removed for other movements. In addition, combined movements are hardly possible with them. Purely mechanical models often have to be adjusted by the examiner by hand, which can mean that the patient table even has to be moved out of the tomograph.

In practice, all of this entails such long examination times that functional MR examinations of the spine have so far been more or less reserved for research purposes.

Just like the positioning aid described at the beginning by J. Tacke et al., an MR positioning aid of the type XD 8001 offered by the company ulrich Medizintechnik, Buchbrunnenweg 12, D-89081 Ulm, as described in a company brochure from 1999, only serves to display the movement sequence of the cervical spine (= H-spine), while the functions of the lumbar spine (= L-spine) cannot be examined with it.

The relatively complicated mechanical structure can only be adjusted manually, so that every time the patient's position needs to be adjusted or changed, the patient and the positioning aid must be pulled out of the tomograph. In addition, this well-known MR positioning aid can only display between four and seven discrete positions of the patient, but not continuous positioning in any intermediate position.

The positioning aid for dynamic cervical spine examinations mentioned at the beginning according to J. Tacke et al., on the other hand, allows for continuous pneumatic movement, whereby any intermediate position in the patient's head position can be continuously displayed for MR tomographic examinations. However, this known positioning aid also does not allow for targeted positioning in the lumbar spine area, as there are only structures in the patient's head area. In addition, in the cervical spine examinations that can be carried out with it, the patient's shoulder is always rigidly positioned, with the upper body already pointing diagonally upwards in the normal position. Unfortunately, this also results in a greatly restricted range of motion in the inclination area of the cervical spine, because the inclination position can only be achieved from a fixed reclination position of the cervical spine.

Mechanically completely different positioning aids are known from the company brochure "Joint Motion Device Operator Manual Siemens" by Chamco, Inc. Cocoa, Florida, USA, 1996. These devices can be used to carry out joint examinations and hip examinations, among other things, whereby the devices are usually designed for open MR tomographs with external access. Although some of the devices described are also compatible with closed high-field magnet systems, the mechanically and hydraulically operated structure is relatively space-consuming and very complex. Differentiated movement options for setting functional positions of the lumbar or cervical spine are not provided. In particular, two different devices are required for lumbar and cervical spine examinations. Likewise, no defined raising of the

Shoulder and/or pelvic region of a patient in supine position is possible with these devices.

In contrast, the object of the present invention is to present a positioning aid for tomographic functional examination of the lumbar spine with the features described at the outset, with which a defined and reproducible kyphosis position of the lumbar spine of a patient to be examined in a tomograph can be precisely set, corrected and fixed from the outside, whereby the positioning aid should be mechanically as simple as possible and, in particular, allow all positioning of the patient required for a functional examination of the lumbar spine to be continuously adjustable even in very confined spaces within a closed tomograph.

According to the invention, this object is achieved in a surprisingly simple but effective manner in that the shoulder plate is designed as a first lifting plate and is pivotably articulated to the base plate via a horizontal joint axis in a direction transverse to the z-direction at its end facing away from the head, that a first lifting bag made of elastic material is arranged between the base plate and the first lifting plate, which can lift the first lifting plate off the base plate on one side by filling it with a fluid, that a further lifting plate which can be lifted off on one side at the foot end is articulated to a carriage which can be moved linearly in the longitudinal direction on the base plate, the joint axis of which runs parallel to the joint axis of the first lifting plate, wherein a further lifting bag is arranged between the carriage and the further lifting plate, that a device for detecting the relative position of the carriage to the first lifting plate is provided, and that the carriage can be locked in a definable relative position to the first lifting plate.

With the help of the fluid-operated first lifting plate, the spine can be continuously raised to any desired position from a normal horizontal position in an aris-specific positioning towards the shoulder area.

upwards. The spine in the lumbar region can also be lifted diagonally upwards towards the foot end of the patient using the additional lifting plate. By providing a movable carriage, which can also be provided on the first lifting plate instead of the additional lifting plate, relative positioning between the two lifting plates in the patient's length is possible, so that any adjustment can be made depending on the patient's size.

The remote-controlled movement of the lifting plates by filling or removing fluid from the corresponding lifting bags is preferably carried out using compressed air. Instead of a pneumatic drive, a hydraulic drive is also conceivable in principle. In any case, the fluid drive guarantees a continuous and jerk-free execution of the movements of the positioning aid required for positioning the patient.

The movements of the device can be remotely controlled from a control console outside the tomograph. During the movement, for example in MR tomographs, the movement sequence can be displayed by using fast sequences in the projection direction ("fluoroscopy"), since the fluidic drive also enables very slow movements. In addition, the respective movement can be stopped at any point, for example for high-resolution sequences.

With the positioning aid according to the invention, reproducible settings are also possible before an operation and for postoperative control examinations as well as for quality assurance.

Particularly in MR examinations, all relevant movements and their combinations can be realized to the physiologically required extent using the positioning aid according to the invention.

Examinations in the normal position can be carried out with practically no loss of quality due to the low height of the positioning aid according to the invention, which is a result of the simple mechanical structure. In addition, for normal examinations of the lumbar spine, it is not necessary to move the patient or move him out. The device can also remain in the tomograph for many other examinations (except possibly for head examinations or mammograms).

A particularly preferred embodiment of the device according to the invention is one in which a shoulder cushion is arranged on the first lifting plate for additionally lifting the upper shoulder area of the patient to be examined. With such a shoulder cushion, the adjustment of the kyphosis position can be significantly improved. A slight kyphosis position of the thoracic spine can also be set up with it.

In order to enable remote-controlled adjustment here too, in a further development of this embodiment the shoulder cushion can be filled with fluid, preferably inflatable.

A particularly advantageous development is one in which the shoulder cushion is essentially wedge-shaped in longitudinal section in a vertical plane containing the z-axis, with the tip of the wedge pointing away from the head end of the device. This ensures that the thorax does not lift off the first lifting plate when the shoulder cushion is raised.

In a further preferred embodiment of the positioning aid according to the invention, a lordosis cushion is provided between the first and the further lifting plate, preferably on the base plate. This enables the patient to be placed in a lordosis position using very simple mechanical means.

In further developments, the lordosis cushion can advantageously be refilled with fluid, preferably inflatable, in order to enable remote-controlled, stepless and jerk-free adjustment.

In addition, in advantageous further developments, the lordosis cushion can be arranged so that it can be moved in the longitudinal direction of the base plate. This provides further degrees of freedom for adapting the positioning aid to the individual body length of the patient to be examined.

Furthermore, the lordosis cushion can have a concave upper side perpendicular to the z-direction, which enables stable positioning of the patient. In particular, this can prevent the patient from rolling sideways.

Another preferred embodiment of the positioning aid according to the invention is an extension plate in which an extension plate is rigidly and detachably attached to the head-side end of the first lifting plate, which has a head cushion on the top of its head-side end for resting the head of the patient to be examined. Sinking of the head causes the cervical spine to recline and counteracts the inclination of the lumbar spine by stretching the ligaments and muscles. However, the extension plate effectively prevents the cervical spine from reclining and thus enables a physiological, pain- and tension-free lordosis position of the lumbar spine of the patient to be examined.

A further preferred embodiment of the positioning aid according to the invention is characterized in that a pelvic cushion is arranged at the height of the pelvis of the patient to be examined to the side of the central axis of the base plate, and that on the same side at a distance from the central axis in the foot area of the patient to be examined, a preferably padded deflection device, in particular a deflection rod for deflecting the feet of the patient to be examined from the longitudinal direction of the base plate, is arranged.

This allows a defined lateral flexion of the lumbar spine using very simple mechanical means.

In further developments, the pelvic cushion can advantageously be refilled with fluid, preferably inflatable, in order to ensure smooth remote control of the position adjustment and to be able to make the necessary adjustment depending on the patient's body size.

In a further advantageous development, the padding of the deflection device can also be filled with fluid, preferably inflatable, which enables remote-controlled adjustment.

A particularly preferred embodiment of the positioning aid according to the invention is characterized in that a reclination plate is pivotably connected to the head-side end of the first lifting plate via a horizontal joint axis running in a direction transverse to the z-direction, and that the reclination plate is carried along via the joint axis when the first lifting plate is raised or lowered, while it is movable in the z-direction at its end facing away from the joint axis, preferably resting on a support surface. This means that the full physiologically possible range of movement of the reclination in the cervical spine area can be represented steplessly using very simple means, in a mechanically inexpensive and particularly space-saving manner.

In a particularly advantageous development of this embodiment, it is provided that an inclination rocker is present in the head region of the patient to be examined, which has a recess in which the reclination plate is received in a normal position, that the inclination rocker is pivotably mounted on two bearing blocks arranged laterally to the left and right of the head region about a common horizontal axis of rotation perpendicular to the z-direction, wherein the axis of rotation is arranged at a vertical distance from the base plate, and that an additional fluid-filled

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A lifting bag, preferably inflatable, is provided between the base plate and the inclination rocker. In this way, with the help of the positioning aid according to the invention, any inclination movement of the head of a patient to be examined is made possible essentially around the physiological pivot point.

Preferably, the distance between the axis of rotation of the inclination rocker and the base plate is such that the head of the patient to be examined can be rotated around its physiological pivot point. This allows the movements to be optimally adapted to the individual physiological conditions of the vertebrate to be examined, in particular human patients.

In a further advantageous embodiment of the above-mentioned embodiment, the articulation of the reclination plate on the first lifting plate is designed such that when the inclination rocker is actuated, the reclination plate is released from the first lifting plate. As a result, the reclination plate is automatically carried along by the inclination rocker during an inclination movement.

This can be achieved particularly easily and inexpensively by connecting the reclining plate to the first lifting plate using bolts connected to the reclining plate, each of which engages in a hook-shaped recess connected to the first lifting plate, preferably opening upwards. This provides a particularly reliable mechanical solution.

Another development of the above-mentioned embodiment for cervical spine examinations is characterized in that a lateral flexion shell is provided in the head area of the patient to be examined, which is connected to the reclination plate via a sliding block so that it can move around a vertical axis, whereby the vertical axis essentially coincides with the physiological axis of rotation of the head of the patient to be examined.

A defined lateral movement of the head can be carried out independently of other movements or in combination with inclination and/or reclination movements and can be fixed in any intermediate position.

This further development can be advantageously designed in that a length compensation shell is arranged within the lateral flexion shell in the normal position and can be moved linearly in a direction parallel to the z-direction. This enables length compensation of the individual neck length of different patients as well as fine adjustment to the physiological movement of the head during inclination and/or reclination.

A further improvement is that a rotation shell is arranged within the length compensation shell so that it can be rotated and fixed around a horizontal axis that is parallel to the z-direction in the normal position. This allows a rotational movement of the head in combination with other movement options.

In order to create an installation option for other functional units, while keeping the overall size of the device as compact as possible, the lateral flexion shell can be designed hollow. The first lifting plate, the further lifting plate and possibly other movable or fixed parts of the device according to the invention can also be designed hollow. In particular, electrical devices in connection with the tomographic examinations to be carried out can then be accommodated in the hollow spaces in a space-saving manner and in the immediate vicinity of the patient to be examined.

If the tomograph used is a magnetic resonance apparatus, one or more surface coils can be arranged, for example, in the cavity of the lateral flexion shell.

In other embodiments, the lower half of a head coil system may be arranged in the cavity and the corresponding upper half of the head coil system may be arranged outside the cavity.

An embodiment of the positioning aid according to the invention is particularly preferred in which a display device is arranged outside the tomograph for optically displaying the position values measured by means of the device for detecting the relative position of the carriage to the first lifting plate. The control console of the tomograph is particularly suitable for this. In this way, the setting of the desired examination position of the patient can be monitored from the outside.

A particularly advantageous development of this embodiment is one in which the device for detecting the relative position of the carriage comprises a sample that emits a signal, in particular a magnetic resonance signal, and is positioned in the rotation axis of the additional lifting plate. This enables extremely precise position control, in particular in MR imaging examinations.

An embodiment of the positioning aid according to the invention is also particularly preferred in which shifts in the relative position of the carriage to the first lifting plate as well as all filling or emptying of lifting bags or other elastic or non-elastic movable hollow bodies of the device can be operated from outside the tomograph. In this way, any desired examination position can be set, changed, varied, corrected or fixed remotely without pushing the patient out of the tomograph.

In order to avoid disturbances of the imaging tomography parts, a further preferred embodiment provides that all power drive and control units of the device according to the invention are

located within the tomograph, preferably in another room.

Finally, a particularly advantageous embodiment is one in which all power drive units can be actively stopped by the patient being examined. Because the patient can actively participate, no additional space needs to be provided for corrective interventions by operating personnel. In addition, the patient's comfort can also be taken into account, and in particular pain caused by overstretching in a certain position can be avoided.

Further advantages of the invention emerge from the description and the drawing. Likewise, the features mentioned above and those listed below can be used according to the invention individually or in groups in any combination. The embodiments shown and described are not to be understood as an exhaustive list, but rather have an exemplary character for the description of the invention.

The invention is illustrated in the drawing and is explained in more detail using exemplary embodiments. They show:

Fig. 1a is a schematic vertical section through an inventive

Positioning aid with patient lying on it in a normal horizontal position;

Fig. 1b Positioning aid according to Fig. 1a in enlarged detail;

Fig. 2a as Fig. 1a, but in horizontal position with lordosis cushion inflated state;

Fig. 2b shows the device according to Fig. 2a in greater detail;

Fig. 3a as Fig. 1a, but in kyphosis position with inflated first and second lifting bag as well as inflated shoulder cushion;

Fig. 3b shows the device according to Fig. 3a in greater detail;

Fig. 4 shows a schematic horizontal section through the inventive

Large positioning aid with pelvic cushion and deflection device for creating a lateral flexion position;

&trade; Fig. 5 is a schematic vertical section through the head end of the

inventive positioning aid with reclination plate and in inclination rocker in reclination position of the reclination plate with the shoulder plate raised;

Fig. 6 the section according to Fig. 5 in greater detail in horizontal nor

mallage of the reclination plate;

Fig. 7 as Fig. 6, but with the inclination rocker in raised inclination

onposition of the cervical spine;

Fig. 8a is a schematic plan view of the reclination plate with sliding

stone for a lateral flexion shell from above;

Fig. 8b shows a vertical section through the median plane parallel to the z-direction;

and

Fig. 9 is a vertical section in a plane perpendicular to the z-axis, which

the joint axis of the inclination rocker as well as the vertical axis of rotation of the sliding block supporting the lateral flexion shell.

In the schematic representation of Fig. 1a, the positioning aid 1 according to the invention can be seen in a horizontally stretched normal position with the patient 2 lying on it.

In Fig. 1b, the positioning aid 1 from Fig. 1a is shown in a schematic vertical section in greater detail without patient 2. A shoulder plate designed as a first lifting plate 4 is pivotably connected to a base plate 3 extending along a z-direction via a horizontal joint axis 5 in a direction transverse to the z-direction at its end facing away from the head. A first lifting bag 6 made of elastic material is arranged between the base plate 3 and the first lifting plate 4, which can lift the first lifting plate 4 off the base plate 3 on one side by filling it with a fluid. Furthermore, a further lifting plate 8 which can be lifted off on one side at the foot end is articulated on a carriage 7 which is linearly movable in the z-direction in a schematically indicated guide 13 on the base plate 3, the joint axis 9 of which runs parallel to the joint axis 5 of the first lifting plate 4, wherein a further lifting bag 10 is arranged between the carriage 7 and the further lifting plate 8, which can also experience an increase in volume by filling it with fluid, in particular by pumping it up with air, which leads to the lifting plate 8 being lifted off on one side from the carriage 7.

At the foot end of the support aid 1, as shown schematically in Fig. 1a, a device 11 is provided for detecting the relative position of the carriage 7 to the first lifting plate 4. The carriage 7 can then be locked in any desired relative position to the first lifting plate 4 by means of a locking device 12, which is also only shown schematically.

Furthermore, Fig. 1 b shows a shoulder cushion 14 which is arranged on the first lifting plate 4 and serves to support the shoulder of the patient 2 to be examined. The shoulder cushion 14, like the two lifting bags 6, 10, can be filled with fluid, preferably inflatable.

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Furthermore, a lordosis cushion 15, which can also be filled with fluid, is arranged between the first lifting plate 4 and the further lifting plate 8 on the base plate 3, which is displaceable in the longitudinal direction of the base plate 3 and has a concave surface transverse to the z-direction when inflated.

An extension plate 16 is removably and rigidly attached to the head-side end of the first lifting plate 4, which has a head cushion 17 on the upper side of its head-side end for supporting the head of the patient 2 to be examined.

Finally, on the underside of the first lifting plate 4, at the head end, an upwardly open hook-shaped recess 18 can be seen in Fig. 1b, which is rigidly connected to the first lifting plate 4 and whose significance is explained in more detail below.

Figures 2a and 2b show the horizontal position with the lordosis cushion 15 inflated and filled with fluid, respectively. The lifting bags 6 and 10 are emptied in this position so that the first lifting plate 4 and the further lifting plate 8 lie horizontally flat. This allows the patient 2 to be placed in a position with a completely hunched back. The patient 2 is prevented from tipping sideways off the lordosis cushion 15 on the one hand by the concave top of the lordosis cushion 15 mentioned above, but not visible in the illustration. On the other hand, such tipping is generally not to be feared even without the concave shape, since the lower part of the back still rests stably on the first lifting plate 4.

In Figures 3a and 3b, the positioning aid 1 according to the invention is shown in the kyphosis position, in which the first lifting bag 6, the further lifting bag 10 and the shoulder cushion 14 are inflated or filled with fluid. As can be seen from the drawing, the shoulder cushion 14 has a substantially wedge shape in the longitudinal section in the vertical plane shown in the drawing, with the tip of the wedge pointing away from the head end of the patient 2.

In the kyphosis position, the thorax area of the patient 2 is raised diagonally upwards by raising the first lifting plate 4 due to the inflated first lifting bag 6. In addition, the pelvic and thigh area of the patient 2 is raised diagonally upwards in the opposite direction by raising the other lifting plate 8 due to the inflated other lifting bag 10. It is essential that the pelvis and the associated lower part of the spine (= sacrum) are tilted forwards in a rotating manner, because otherwise the movement only affects the joint between the thigh and pelvis.

With the help of the movable carriage 7, the relative position between the first lifting plate 4 and the further lifting plate 8 can be individually adjusted to the height of the patient 2. The detection device 11 then shows the relative position precisely to the outside. As soon as the correct position is reached, it can be locked with the locking device 12.

When placing patient 2 on the positioning aid 1, a rough pre-setting of the position can be carried out outside the tomograph. For this purpose, the joint axis 9, which should be at the level of an easily palpable anatomical point (= greater trochanter), is clearly marked on the outside. In applications in MR tomography, a sample tube with signal-generating material can be located exactly in this axis of rotation, the position of which within the tomograph can then be made visible on an overview image. The sample tube, which is not shown in detail in the drawing, must be at a precisely defined point below the sacrum. If it is not, the distance between the sample tube and a target point is measured on the screen. A subsequent position correction can then be carried out at any time without having to move patient 2 out of the tomograph again and take a new overview image after changing the position accordingly.

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The currently set position of the slide 7 can be read on a display device. If the patient 2 is now asked to do a slight "bridge", the lock on the locking device 12 can be released and the slide 7 can be moved by the required distance. If such a procedure is not possible, for example due to the patient 2's lack of mobility, the lordosis cushion 15 can also be pumped up until the patient 2's buttocks are slightly raised and the slide 7 is released.

The representation of a lateral flexion is shown in Fig. 4. For this purpose, a pelvic cushion 19 is arranged at the height of the pelvis of the patient 2 to the side of the central axis of the base plate 3, which in turn can be filled with fluid. On the same side on which the pelvic cushion 19 is located, at a distance from the central axis in the foot area of the patient 2, a padded deflection device 20 with a deflection rod 21 for deflecting the feet of the patient 2 from the longitudinal direction of the base plate 3 is arranged. The padding of the deflection device 20 can in turn be filled with fluid.

However, lateral flexion of the lumbar spine is only used in rare cases (mostly in cases of listhesis) in conventional myelography. It would therefore be entirely acceptable if a little extra manual work was required to position the patient in these cases. After inflating the pelvic cushion 19, the patient's straight legs are brought into the desired position with the deflection device 20 by moving them in the direction of one of the two double arrows in Fig. 4 and the deflection device 20 is fixed in this position. Here, too, adaptation to different patient sizes is easily possible.

In Fig. 5, following the first lifting plate 4 raised by the inflated first lifting bag 6, one can see a reclining plate 23 which can be pivoted about a horizontal joint axis 22a running in a direction transverse to the z-direction and which is articulated to the first lifting plate 4 via a bolt 22 which engages in the hook-shaped recess 18. When lifting

When the first lifting plate 4 is raised or lowered, the reclining plate 23 is carried along via the joint axis 22a, while at its end facing away from the joint axis 22a it rests on a support surface 24 such that it can be moved in the z-direction.

In the position shown in Fig. 5, a reclination of the cervical spine is achieved, whereby the head of the patient 2 to be examined (not shown here) is tilted obliquely backwards, while the thorax region points obliquely upwards over the first lifting plate 4.

Furthermore, in Fig. 5, an inclination rocker 25 is provided, which has a recess 26 in which the reclination plate 23 is received in the normal position shown in Fig. 6.

The inclination rocker 25 is mounted on two bearing blocks 27, 27' arranged laterally to the left and right of the head area so as to be pivotable about a common horizontal axis of rotation 28 perpendicular to the z direction, the axis of rotation 28 being arranged at a vertical distance from the base plate 3. In addition, a lifting bag 29 which can be filled with fluid and is usually inflatable is provided between the inclination rocker 25 and the base plate 3 and which, as shown in Fig. 7, causes the inclination rocker 25 with the reclination plate 23 accommodated therein to be lifted on one side and thus pivots about the axis of rotation 28. The bolt 22 is pulled upwards out of the hook-shaped opening 18 and removed in the z direction towards the head end of the device 1.

As can be seen from Fig. 7, in order to generate the reclination position, the first lifting plate 4 is in the normal horizontal position with the first lifting bag 6 not inflated.

The vertical distance of the rotation axis 28 of the inclination rocker 25 from the base plate 3 is such that a rotation of the head of the person to be examined

corresponding patient 2 can essentially be carried out around his physiological pivot point.

In the top view of the reclination plate 23 shown in Fig. 8a, an imaginary pivot point 36 is shown around which the lateral flexion movement takes place. In addition, Fig. 8a shows two bearing blocks 37, 37' arranged on both sides for receiving the hinge pin 22.

Furthermore, Fig. 8a shows a curved guide rail 38 connecting the two bearing blocks 37, 37', on which a sliding block 31 can be moved in the direction of the double arrow about an axis that is vertical in the normal position. In a sagittal section through the vertical center plane of the reclination plate 23 shown in Fig. 8a, as reproduced in Fig. 8b, the guide rail 38 can be seen in cross section.

Finally, Fig. 9 shows a vertical section perpendicular to the z-axis, which contains the rotation axis 28 of the inclination rocker 25. A lateral flexion shell 30 is supported on the sliding block 31, which sits on the reclination plate 23, so that it can rotate about the vertical axis 32. This should coincide as far as possible with the physiological rotation axis of the head of the patient 2 to be examined. In the embodiment shown in the drawing, the lateral flexion shell 30 is hollow and can contain one or more surface coils or, for example, a lower half of a head coil system for MRI in its cavity 35.

Inside the lateral flexion shell 30 there is a length compensation shell 33 which can be moved linearly in a direction parallel to the z-direction in the normal position. Inside the length compensation shell 33 there is a rotation shell 34 which can be rotated and fixed about a horizontal axis which is parallel to the z-direction in the normal position. This means that all possible movements of the human head are defined, reproducible and lockable.

Claims (24)

1. Positioning aid ( 1 ) for tomographic functional examination of vertebrates, in particular humans, with a base plate ( 3 ) extending along a z-direction parallel to the tomograph axis, which is preferably positively connected to a movable patient bed of a tomography apparatus, wherein a shoulder plate is attached to the base plate ( 3 ) in the thorax region of the patient ( 2 ) to be examined, which enables a steadily increasing position of the thorax region of the patient ( 2 ) to be examined in the direction of the head relative to the base plate ( 3 ), characterized in that
that the shoulder plate is designed as a first lifting plate ( 4 ) and is pivotably connected to the base plate ( 3 ) via a horizontal joint axis ( 5 ) in a direction transverse to the z-direction at its end facing away from the head,
that between the base plate ( 3 ) and the first lifting plate ( 4 ) a first lifting bag ( 6 ) made of elastic material is arranged, which can lift the first lifting plate ( 4 ) from the base plate ( 3 ) on one side by filling it with a fluid,
that a further lifting plate ( 8 ) which can be lifted off on one side at the foot end is articulated on a carriage ( 7 ) which can be moved linearly in the longitudinal direction on the base plate ( 3 ), the articulation axis ( 9 ) of which runs parallel to the articulation axis ( 5 ) of the first lifting plate ( 4 ), wherein a further lifting bag ( 10 ) is arranged between the carriage ( 7 ) and the further lifting plate ( 8 ),
that a device ( 11 ) is provided for detecting the relative position of the carriage ( 7 ) to the first lifting plate ( 4 ), and that the carriage ( 7 ) can be locked in a definable relative position to the first lifting plate ( 4 ). 2. Device according to claim 1, characterized in that a shoulder cushion ( 14 ) for supporting the shoulder of the patient to be examined ( 2 ) is arranged on the first lifting plate ( 4 ). 3. Device according to claim 2, characterized in that the shoulder cushion ( 14 ) can be filled with fluid, preferably inflatable. 4. Device according to claim 2 or 3, characterized in that the shoulder cushion ( 14 ) is essentially wedge-shaped in longitudinal section in a vertical plane containing the z-axis, the wedge tip pointing away from the head end of the device ( 1 ). 5. Device according to one of the preceding claims, characterized in that a lordosis cushion ( 15 ) is provided between the first lifting plate ( 4 ) and the further lifting plate ( 8 ), preferably on the base plate ( 3 ). 6. Device according to claim 5, characterized in that the lordosis cushion ( 15 ) can be filled with fluid, preferably inflatable. 7. Device according to claim 5 or 6, characterized in that the lordosis cushion ( 15 ) is arranged to be displaceable in the longitudinal direction of the base plate ( 3 ). 8. Device according to one of claims 5 to 7, characterized in that the lordosis cushion ( 15 ) has a concave upper side transverse to the z-direction. 9. Device according to one of the preceding claims, characterized in that an extension plate ( 16 ) is removably and rigidly fastened to the head-side end of the first lifting plate ( 4 ), which extension plate has a head cushion ( 17 ) on the upper side of its head-side end for supporting the head of the patient ( 2 ) to be examined. 10. Device according to one of the preceding claims, characterized in that a pelvic cushion ( 19 ) is arranged at the level of the pelvis of the patient to be examined ( 2 ) to the side of the central axis of the base plate ( 3 ), and that on the same side at a distance from the central axis in the foot region of the patient to be examined ( 2 ) a preferably padded deflection device ( 20 ), in particular a deflection rod ( 21 ) for deflecting the feet of the patient to be examined ( 2 ) from the longitudinal direction of the base plate ( 3 ) is arranged. 11. Device according to claim 10, characterized in that the pelvic cushion ( 19 ) can be filled with fluid, preferably inflatable. 12. Device according to claim 10 or 11, characterized in that the padding of the deflection device ( 20 ) can be filled with fluid, preferably inflatable. 13. Device according to one of the preceding claims, characterized in that a reclining plate ( 23 ) is pivotably articulated on the head-side end of the first lifting plate ( 4 ) via a horizontal joint axis ( 22a ) running in a direction transverse to the z-direction, and that the reclining plate ( 23 ) is carried along via the joint axis ( 22a ) when the first lifting plate ( 4 ) is raised or lowered, while it is movable in the z-direction at its end facing away from the joint axis ( 22a ), preferably resting displaceably on a support surface ( 24 ). 14. Device according to claim 13, characterized in that an inclination rocker ( 25 ) is provided in the head region of the patient to be examined ( 2 ), which has a recess ( 26 ) in which the reclination plate ( 23 ) is received in a normal position, that the inclination rocker ( 25 ) is pivotably mounted on two bearing blocks ( 27 , 27 ') arranged on both sides of the head region about a common horizontal axis of rotation ( 28 ) perpendicular to the z-direction, wherein the axis of rotation ( 28 ) is arranged at a vertical distance from the base plate ( 3 ), and that an additional lifting bag ( 29 ) that can be filled with fluid and is preferably inflatable is provided between the base plate ( 3 ) and the inclination rocker ( 25 ). 15. Device according to claim 14, characterized in that the distance of the axis of rotation ( 28 ) of the inclination rocker ( 25 ) from the base plate ( 3 ) is dimensioned such that a rotation of the head of the patient to be examined ( 2 ) about its physiological pivot point can take place. 16. Device according to claim 14 or 15, characterized in that the articulation of the reclination plate ( 23 ) on the first lifting plate ( 4 ) is designed such that when the inclination rocker ( 25 ) is actuated, the reclination plate ( 23 ) is released from the first lifting plate ( 4 ). 17. Device according to claim 16, characterized in that the articulation of the reclining plate ( 23 ) to the first lifting plate ( 4 ) is realized by one or more bolts ( 22 ) connected to the reclining plate ( 23 ), each of which engages in a hook-shaped recess ( 18 ) connected to the first lifting plate ( 4 ), preferably open at the top. 18. Device according to one of claims 13 to 17, characterized in that a lateral flexion shell ( 30 ) is provided in the head region of the patient to be examined ( 2 ), which is connected to the reclination plate ( 23 ) via a sliding block ( 31 ) so as to be movable about a vertical axis ( 32 ), wherein the vertical axis ( 32 ) substantially coincides with the physiological axis of rotation of the head of the patient to be examined ( 2 ). 19. Device according to claim 18, characterized in that within the lateral flexion shell ( 30 ) a length compensation shell ( 33 ) is arranged to be linearly movable in a direction parallel to the z-direction. 20. Device according to claim 19, characterized in that within the length compensation shell ( 33 ) a rotation shell ( 34 ) is arranged so as to be rotatable and fixable about a horizontal axis parallel to the z-direction. 21. Device according to one of claims 18 to 20, characterized in that the lateral flexion shell ( 30 ) is hollow. 22. Device according to claim 21, characterized in that the tomograph is a magnetic resonance apparatus and that one or more surface coils are arranged in the cavity ( 35 ) of the lateral flexion shell ( 30 ). 23. Device according to claim 21, characterized in that the tomograph is a magnetic resonance apparatus, and that a lower half of a head coil system is arranged in the cavity ( 35 ) of the lateral flexion shell ( 30 ) and the corresponding upper half of the head coil system is arranged outside the cavity ( 35 ). 24. Device according to one of the preceding claims, characterized in that a display device for optically displaying the position values measured by means of the device ( 11 ) for detecting the relative position of the carriage ( 7 ) to the first lifting plate ( 4 ) is arranged outside the tomograph. 25. Device according to claim 24, characterized in that the device ( 11 ) for detecting the relative position of the carriage ( 7 ) comprises a signal-emitting sample, in particular a magnetic resonance signal-emitting sample, which is positioned in the axis of rotation ( 9 ) of the further lifting plate ( 8 ). 26. Device according to one of the preceding claims, characterized in that displacements of the relative position of the carriage ( 7 ) to the first lifting plate ( 4 ) as well as all fillings or emptyings of lifting bags or other elastic hollow bodies of the device ( 1 ) can be actuated from outside the tomograph. 27. Device according to one of the preceding claims, characterized in that all power drive and control units of the device ( 1 ) are arranged outside the tomograph, preferably in another room. 28. Device according to one of the preceding claims, characterized in that all power drive units can be actively stopped by the patient to be examined ( 2 ).