Lifting drive for a radiation filter in a mammography device

A lifting drive for a radiation filter in a mammography device is provided. The lifting drive includes a recording apparatus that accommodates the radiation filter. The recording apparatus is embodied so that the radiation filter is operatively supported to allow movement for executing a lifting movement in at least one lifting direction. A first drive element is operable to create a drive movement. A first movement transmission element is operable to transmit the drive movement to the recording apparatus. The recording apparatus is operable to convert the drive movement into the lifting movement. A shape of the first movement transmission element is operable to be changed, so that the drive movement is able to be transmitted over different paths.

This patent document also claims the benefit of DE 10 2006 017 310.4, filed Apr. 12, 2006, which is also hereby incorporated by reference.

BACKGROUND

The present embodiments relate to a lifting drive for a radiation filter in a mammography device. The present embodiments also relate to a mammography device with a lifting drive.

Mammography devices may be used for fluoroscopy of an object to be examined, for example, a female breast. Mammography devices may feature a radiographic source and a radiation detector. The object to be examined is positioned between the radiographic source and the detector. Scattered radiation is predominantly caused by deflection of the examination rays in the x-rayed object under examination. Scattered radiation is especially problematic when x-raying thicker objects. To reduce the radiation scattering at the detector, an anti-scatter grid is usually arranged behind the object under examination and in front of the detector.

Anti-scatter grids may cause stripes or grids of noise on the examination image recorded in the detector. To reduce or eliminate these disturbance stripes, the anti-scatter grid is agitated slightly during the examination.

DE 3316003 A1 discloses a device for rectifying radiation scatter with an anti-scatter grid. The anti-scatter grid is moved back and forth once by a drive element as an image is recorded. A drive movement is created in a drive motor and converted via a fixed gear into an oscillating lifting movement of the anti-scatter grid.

SUMMARY

The present embodiments may obviate one or more of the drawbacks or limitations inherent in the related art. For example, in one embodiment, a lifting drive for a radiation filter in a mammography device is provided, and a mammography device provides greater design scope for the arrangement of components of the lifting drive or the components of the mammography device.

In one embodiment, a lifting drive is suitable and/or embodied for a radiation filter in a mammography device. The radiation filter is embodied as an anti-scatter grid and/or as an arrangement of a number of anti-scatter grids and/or as an x-ray grid. The radiation filter complies with the characteristic values in the required framework of DIN Standard 6826. In an alternative embodiment, the lifting drive may be used in other, especially medical, investigation devices in which a radiation filter is moved.

In one embodiment, the lifting drive includes a recording apparatus embodied to accommodate the radiation filter. When an examination is being undertaken, especially when an examination image is being recorded, the recording apparatus is arranged so that it is stationary, especially stationary relative to the mammography device and/or examination device.

The mechanical design of the recording apparatus allows the radiation filter to perform a lifting movement in at least one lifting direction relative to the recording apparatus and/or to the detector. The lifting direction is parallel or coplanar to the plane formed by the entry surface and/or the exit surface for the directed examination radiation of the radiation filter. In one embodiment, this involves a linear lifting movement. Alternatively a lifting movement with a curved movement track can also be provided.

The lifting drive includes a first drive apparatus that creates the drive movement. In one embodiment, the drive movement is an oscillating movement. In other embodiments, the drive movement may be a sine-wave drive movement or a saw tooth wave drive movement. In one embodiment, oscillating drive movements are used where the sum of the speed over time is constant and/or essentially constant. The drive apparatus may be a drive unit, which with the aid of a link apparatus, creates from a sine wave movement a linear saw tooth wave movement as the drive movement.

A first movement transmission element is provided. The first movement transmission element transmits the drive movement to the recording apparatus. The first movement transmission element is connected serially in the transmission. The recording apparatus converts the drive movement into the lifting movement.

The first movement transmission element may change its shape and can do this in such a way that the drive movement is transmitted over different curved paths.

The drive element can be placed at any given location. The drive movement is able to be transmitted from any given location via the movement transmission element to the recording apparatus. The drive element does not have to be arranged directly in the recording apparatus or have the element rigidly coupled to the recording apparatus.

In one embodiment, the first movement transmission element is reversible, elastically bendable, and/or plastically bendable. The movement transmission element is resistant to bending or is to be slack. In another embodiment, the first movement transmission element is constructed from individual chain elements.

In one embodiment, the first movement transmission element is a cable pull. The first movement transmission may be a Bowden cable. The Bowden cable includes an internal steel wire or a wire cable. The internal steel wire or wire cable can be laid in a flexible sleeve. The sleeve may be covered with plastic or textile. The sleeve may be a tightly wound, compression-proof wire spiral.

In another embodiment, the first movement transmission element is a hydraulic and/or pneumatic line. The drive movement is implemented pneumatically and/or hydraulically.

Depending on how the movement transmission element is implemented, the first movement transmission element is embodied for transmission of tensile and/or compression forces. The movement transmission element may be embodied for transmission of forces in both directions. The lifting movement is easy to create.

In one embodiment, the movement transmission element forces are only transmitted in one direction. The movement transmission element forces are either tensile forces or compression forces. A second movement transmission element may be provided. The second movement transmission element may be embodied to reset the first movement transmission element. The first and also second movement transmission elements may be embodied as cable pulls, especially Bowden cables.

In one embodiment, a counter force apparatus is arranged in the recording apparatus. The counter force apparatus works against the force or movement transmitted in the first and/or second movement transmission element. The counter force apparatus is a tensile and/or compression spring arrangement.

The combinations of actions able to be implemented include:

The recording apparatus together with the inserted radiation filter can be moved in such a way that examinations can be undertaken without this radiation filter. The recording apparatus is moved from an examination position into a rest position. The radiation filter is embodied so that it can be moved out of the x-ray recording area.

When the recording technology is changed, no major conversion measures are required at the examination device, especially at the mammography device. Such conversion work is for example usually necessary if, instead of a digital detector with radiation filter, a stereotaxy examination with an additional CCD camera or a tomosynthetic examination is to be performed.

The lifting drive with the carriage may include a few or all of the previously described features.

In one embodiment, the lifting drive is equipped with a second drive apparatus that is embodied and/or arranged to move the carriage.

The second drive apparatus is an electric motor that moves the carriage using a toothed bar or a toothed belt. The carriage is guided on precision shafts with slide bearings or similar, especially so that a play-free or almost play-free guidance is guaranteed. In alternative embodiments, miniature linear guides are used to guide the carriage.

The transfer of the recording apparatus from the examination position to the rest position is a deactivation of the radiation filter or of the grid.

In one embodiment, the carriage and/or the recording apparatus are arranged to allow movement relative to the first and/or the second drive apparatus. The relative movement to the first recording apparatus is only achieved by the drive movement that is transmitted via the deformable movement transmission element. The carriage can be implemented together with the recording apparatus in a very light or filigree construction since the drive apparatus is not transported on the carriage. The first drive element for the lifting movement of the radiation filter can be placed at almost any given position. From this almost any given position, the drive movement generated is transmitted via the movement transmission element to the radiation filter.

In one embodiment, a mammography device includes a lifting drive as described above with the radiation filter as an anti-scatter grid and/or x-ray grid.

In one embodiment, the deactivation of the radiation filter is controlled, for example, by a simple program selection and is able to be initiated by software. The mammography device is able to be operated with a high level of automation, since the operator does not have to make any manual and/or mechanical settings in advance in order to execute a specific recording technology.

DETAILED DESCRIPTION

FIG. 1shows a lifting drive1for an anti-scatter grid2which is supported to allow movement in a recording apparatus3. The recording apparatus3is embodied as a grid plate, especially as a plate made from sheet metal. The anti-scatter grid2is a slatted shutter or a two-dimensional grid with a honeycomb or cross structure.

To move the anti-scatter grid2during the examination, especially to avoid noise stripes or other artifacts, two guide nipples4are provided in the recording apparatus3. The two guide nipples4may be provided on the grid plate. The two guide nipples4engage in two longitudinal holes of the anti-scatter grid2or a frame construction for fixed support of the anti-scatter grid2. The anti-scatter grid2is able to move in the direction of extension of the longitudinal holes5oscillating back and forth relative to the recording apparatus3.

To generate this relative movement between the anti-scatter grid2and the recording apparatus3, a first electric motor6is provided which uses a linkage apparatus7to transform the sine-wave motor movement of the first electric motor6into a linear saw tooth movement. This drive movement generated by the first electric motor6and transformed by the linkage apparatus7is transmitted via a flexible movement transmission element in the form of a Bowden cable8to the recording apparatus3. The Bowden cable8has a sleeve. One end of the Bowden cable8is fixed to the recording apparatus3and the other end is fixed to the linkage apparatus7. One end may be fixed to the grid plate. The linear saw tooth movement is transferred via the Bowden cable8to the recording apparatus3. In one embodiment, the steel cable guided in the sleeve of the Bowden cable8is permanently coupled to the anti-scatter grid2. The anti-scatter grid2can be moved back and forth by the movement of the steel cable in the Bowden cable8along the longitudinal holes5.

Because of the flexibility of the Bowden cable8, it is better able to transfer tensile forces than compressive forces. To guarantee a resetting of the anti-scatter grid2in the compression direction of the Bowden cable, optional compression or tensile springs are provided that are arranged so that they act against the compression force or the tensile movement of the Bowden cable8, especially of the steel cable in the Bowden cable8.

In one embodiment, another Bowden cable which is arranged to run in the opposite direction to the Bowden cable8is used. The oscillating movement of the anti-scatter grid2is created by an alternating transmission of tensile forces by the Bowden cables.

The recording apparatus3is embodied in the lifting drive1as a moveable carriage. The recording apparatus3is guided captively on two precision shafts9that are arranged in parallel to each other. The recording apparatus3and the anti-scatter grid2are moved sideways in one direction of movement so that the anti-scatter grid2is deactivated.

The anti-scatter grid2is deactivated when the anti-scatter grid2is withdrawn from a detector area. The amount of movement may be around the width of the anti-scatter grid2in the direction of movement. The recording apparatus3can be moved manually on the precision shafts9or by, as shown inFIG. 1-6, a second electric motor10. The second electric motor10moves the recording apparatus3embodied as a carriage via a toothed belt11.

The first electric motor6, the link apparatus7, and the second electric motor10are arranged below the precision shafts9. The contours of these components do not interfere with the movement of the recording apparatus3.

The recording apparatus3embodied as a carriage is moved in relation to the stationary components first electric motor6, link device7, and second electric motor10. The flexible Bowden cable8makes it possible to execute the displacement movement without separating the movement transmission between the drive unit for the lifting movement, for example, first electric motor6and link device7, and recording apparatus3.

FIGS. 2 and 3show the lifting drive1. The direction of lift is indicated inFIG. 3by a black double-ended arrow.

The recording apparatus3and the anti-scatter grid2, as shown inFIG. 4, are in an end position on the right hand side.FIG. 4shows a detector12for which the detection area is positioned below the anti-scatter grid2. In the left end position of the recording apparatus3, the detector12in the measurement or detector area is no longer covered by the anti-scatter grid2. In this end position the anti-scatter grid2is deactivated.

FIGS. 5 and 6show the lifting drive1with an activated or with a deactivated anti-scatter grid2.FIG. 5shows the activated state.FIG. 6shows the deactivated operating state.

As shown inFIGS. 5 and 6, a flexible movement transmission element such as the Bowden cable8is used. The Bowden cable8allows the drive unit for the lifting movement of the anti-scatter grid, for example, the first electric motor6and the link apparatus7, to be positioned at any point independent of the recording apparatus3.

A lifting drive1includes a drive unit, which is used for the lifting movement of the anti-scatter grid2that is arranged stationary in relation to the examination device, especially to the mammography device. The drive unit can remain in place both for an activated and also a deactivated anti-scatter grid2because of the connection between anti-scatter grid2or recording apparatus3and drive unit via the Bowden cable8.