Imaging plate support for recording of radiographs

The invention relates to a support for holding Xray or other medical imaging plates.

Similar supports are well known, but suffer from the disadvantages that they are either very large and intrusive structures to use and store, are over-complicated in use, or are insufficiently stable to guarantee blur-free radiographic recording. Supports typically used for lateral Xray recording in resuscitation environments are heavy and cumbersome to move, take up space around an intensive care bed or stretcher equivalent to at least one person, and also occupy the same large space while not in use.

An object of this invention is to provide a support for medical image media which at least mitigates some of the above problems. Applications include: recording of Xrays of reclining patients in intensive care; gastrointestinal imaging such as barium enema procedures; and routine imaging in orthopaedics.

Accordingly this invention provides an Xray imaging plate support including a baseplate and one or more channelled support posts that can be mounted to the baseplate preferably by means of magnets incorporated in or attached to their bases, so that preferably any width of Xray plate can be accommodated as limited by the width of the baseplate. In one embodiment of the invention the post bases incorporate magnets which provide a substantially permanent magnetic holding strength. The holding strength of the magnet is preferably chosen so that the post may be repositioned while retaining substantial resistance to tipping.

In a preferred embodiment the magnetic holding force is modified by means of a spacer or coating between the magnetic base and ferromagnetic plate. This feature allows a compromise between the holding force achieved by the magnet and the ability to reposition the support, while using manufactured magnets which of themselves may be unsuitable due to excessive strength.

In an alternative embodiment the magnets have a holding strength which is switchable between a substantially low to a substantially high state. This embodiment allows for a maximum holding strength while the Xray plate is required to be immobile, but a lower holding strength when the posts need to be manoeuvred. This embodiment allows the accessible field strength of the magnets to be safe at all times with respect to the behaviour of pacemakers and other devices sensitive to magnetic fields.

Preferably, the baseplate is made of a ferromagnetic material such as suitably coated mild steel. Preferably, the support posts may be made from any material compatible with the clinical setting in which the device is used. Preferably, The support posts have a number of channels of differing widths so as to accommodate Xray plates of differing thicknesses. Alternatively, a single channel may be equipped with a spring so as to accommodate a variety of plate thicknesses.

The use of a ferromagnetic baseplate allows a variety of accessories to be positioned by means of magnetic bases. One such accessory is a magnification target which is an object of known size that can be positioned close to a patient's anatomy during Xray exposure thereby providing a means for measuring dimensions of anatomical features from the recorded Xray. This can be important when, for example, choosing the size of an orthopaedic implant.

A preferred embodiment of the invention will now be described with reference to the accompanying drawing in which:

FIGURE 1 shows a pair of support posts of the current invention mounted to the baseplate of the current invention, holding a typical medical imaging plate.

FIGURE 2 shows the baseplate of Figure 1 in detail.

FIGURE 3 shows the support post of Figure 1 in detail.

FIGURE 4 shows the support of the current invention in use with the baseplate inserted beneath a patient's bed support in order to effect a lateral Xray recording.

FIGURE 5 shows the magnetic base with spacer affixed to optimise the holding strength for stability and manoeuvrability.

FIGURE 6 shows an alternative embodiment of a post according to the present invention having a magnetic base which is mechanically switchable between high and low holding strengths.

FIGURE 7 shows an alternative embodiment of a post of the present inventor in which the magnetic holding force substantially increases when the post approaches the ferromagnetic base.

FIGURE 8 shows an alternative embodiment of a post of the present invention having a means for adjustment of the imaging plate height.

FIGURE 9 shows a magnetically positionable magnification target used for surgical templating that is compatible with the ferromagnetic baseplate.

In Figure 1 the support is shown to comprise a pair of channelled support posts 1 each attached to a magnetic base 2.

The posts are located on a preferably flat baseplate 3 made of ferromagnetic material, such that they can be positioned in a versatile manner at any position and angle on the baseplate 3. This construction enables the posts to hold firmly an Xray or other medical imaging plate 4.

Figure 2 shows the flat baseplate 3 in detail which in this preferred embodiment is made from powder-coated mild steel and is equipped with an aperture 5 that can be used as a convenient handle for manipulation or storage via hanging.

Figure 3 shows a support post 1 in detail equipped with magnetic base 2. In this embodiment the post has been provided with two channels of different widths 6, 7 to accommodate imaging plates of different thicknesses. The posts could be equipped with more or less channels, or a single wide channel incorporating a spring so as to firmly locate imaging plates of varying thicknesses.

Figure 4 shows a view of the invention in one of its intended applications. In this case the flat baseplate 3 is slid under the patient's 8 mattress 9 on their bed/stretcher 10 and the support posts 1, 2 have been placed to hold an imaging plate 4 so as to effect recording of a lateral (horizontal) Xray view.

Figure 5 shows the magnetic base 2 with spacer 11 to optimise the holding strength for stability and ability to reposition. This allows the use of off the shelf permanent magnets which might otherwise be too strong for the intended application.

Figure 6 shows an alternative embodiment of the a support post in which the support post 1 incorporates a slot 6 and a magnetic base 2 whose holding strength can be varied substantially by means of a mechanical switch 12 of known design. The switch switches a magnet of the magnetic base between an engaged and a non- engaged position.

Figure 7 shows an embodiment of a post 1 in which the accessible magnetic field strength is limited for reasons of safety when not in use by a spring mechanism 13 and plunger 14 that substantially reduces the distance between the magnetic base 2 and ferromagnetic baseplate 3 when the post 1 is substantially in place; this reduction in distance substantially increasing the magnetic holding force when in place. This is achieved by the spring 13 retaining the support in the position shown in Figure 7 until such time as the operator pushes the support towards the base, thereby overcoming the spring force to allow the magnet to engage the support with the base.

Figure 8 shows an embodiment of a post 1 having a means for adjustment of the imaging plate's 4 height by means of a peg 15 which is positioned in one of a plurality of holes 16 arranged at varying heights within the post slots 6.

Figure 9 shows an imaging accessory in the form of a calibration device that can be placed securely at any position on the ferromagnetic baseplate 3 by means of a magnetic base 2 which may have a spacer 11 to modify its holding strength. In this preferred embodiment the calibration object is a metallic ball of known diameter 17 that is mounted to a plurality of substantially radiolucent posts 18 and clamps 19, this

system permitting versatile location of the calibration object close to the patient's anatomy.

In an alternative embodiment the target could be another commercially available target such as a planar array of metallic calibration targets such as discs or rulings, made compatible with the ferromagnetic baseplate of this invention by mounting on a magnetic baseplate.

In a further alternative embodiment the calibration target could be a commercially available metallic ball mounted on a plurality of articulating radiolucent segments forming a flexible arm, made compatible with the ferromagnetic baseplate of this invention by mounting on a magnetic baseplate.

hi a yet further alternative embodiment the accessory may be a detector, alignment, measurement or shielding device.