Patent Description:
The present disclosure relates to an X-ray scaling device.

Orthopedic digital templating enables healthcare professionals to determine the correct size of a prosthesis to be used for a patient prior to surgery. Digital templating yields the best sizing accuracy if scaling devices are used within the x-ray image. A scaling device includes a scaling marker that has a known geometry and is visible in a radiographic image. <CIT>, <CIT>, <CIT> and <CIT> relate to scaling devices. The marker is used by digital templating software to accurately scale the image. However, users can compromise the image scaling of the software due to improper scaling marker placement.

The present inventors have recognized that improper placement and, additionally or alternatively, variability of placement of a scaling marker can compromise the accuracy of image scaling in orthopedic digital templating. Devices, systems, and methods for facilitating consistent and proper scaling marker placement would therefore be desirable. Accordingly, the present teachings provide for a device for consistent and proper scaling marker placement. The invention provides a scaling device as defined in claim <NUM>. The scaling device comprises a main body having at least one anatomical registration feature configured to be aligned with a selected anatomical feature wherein the main body is conformable to the selected anatomical feature, wherein the main body further comprises a scaling marker and a scaling marker pathway that is selectively oriented with respect to the anatomical registration feature and can facilitate repeatable gross placement of a scaling marker relative to the selected anatomical feature wherein the scaling marker pathway has a first end and an opposed second end and wherein the scaling marker is selectively displaceable along the scaling marker pathway about and between the first end and the second end to enable fine placement of the scaling marker relative to the selected anatomical structure.

The present teachings may be used in a method which is not claimed for imaging a selected anatomy comprising the steps of: securing the main body with respect to an anatomical registration feature; adjusting a scaling marker about and between a first end and a second end of a scaling marker pathway to fine-tune placement of the scaling marker relative to the selected anatomy; and capturing and scaling an image of the selected anatomy.

The present teachings provide for a device for consistent and proper scaling marker placement. Such a device can facilitate consistent placement of a scaling marker relative to an anatomical structure, thereby reducing or eliminating image scaling error introduced through variability of scaling marker placement. Additionally or alternatively, such a device can provide for proper scaling marker placement relative to an anatomical structure for a given image, thereby reducing or eliminating image scaling error due to improper scaling marker placement.

With initial reference to <FIG>, a system <NUM> comprises a data collection unit <NUM> and a scaling device <NUM>. The data collection unit <NUM> and scaling device <NUM> of the present teachings can be used in combination for anatomical registration prior to and/or during a surgical procedure.

In one aspect illustrated in <FIG>, the scaling device <NUM> can comprise a main body <NUM> having an anatomical registration feature <NUM> defined therein. The main body can further comprise a scaling marker pathway <NUM>. The scaling marker pathway <NUM> can be selectively oriented with respect to the anatomical registration feature <NUM> and can facilitate repeatable gross placement of a scaling marker <NUM> relative to the selected anatomical feature. The scaling marker pathway <NUM> can have a first end and an opposed second end. The scaling marker <NUM> can be selectively displaceable along the scaling marker pathway <NUM> about and between the first end and the second end to enable fine placement of the scaling marker <NUM> relative to the selected anatomical structure. The main body <NUM> can be substantially radiolucent. The scaling marker <NUM> can be substantially radiolucent and, additionally or alternatively, can be a sphere. In operation, the main body <NUM> of the scaling device <NUM> can be positioned on a patient such that the anatomical registration feature <NUM> can be aligned with a selected anatomical feature, facilitating gross placement of the scaling marker <NUM> relative to the selected anatomical structure. An operator can then selectively displace the scaling marker <NUM> along the scaling marker pathway <NUM> about and between the first end and the second end so that the position of the scaling marker <NUM> can be fine-tuned prior to image capture by the data collection unit <NUM>.

In one aspect illustrated in <FIG>, the scaling marker pathway <NUM> can comprise a pocket <NUM>. The pocket <NUM> can be disposed in and/or on the main body <NUM>. In an additional or alternative aspect illustrated in <FIG>, the scaling marker pathway <NUM> can comprise a pocket <NUM> that can be offset from the main body <NUM>. The scaling marker <NUM> can be disposed in the pocket <NUM> and the scaling marker <NUM> can be selectively displaceable about and between the first end and the second end of the pocket <NUM>.

In another aspect, the scaling device <NUM> can further comprise a scaling marker enclosure <NUM>. The scaling marker pathway <NUM> can comprise a first side of a fastener <NUM> such as, for example and without limitation, a hook-and-loop type fastener, snaps, buttons, or any other suitable fastener known in the art. The scaling marker enclosure <NUM> can further comprise a second, mating side of the fastener <NUM>. In operation, an operator can adjust the location of the scaling marker enclosure <NUM> along the scaling marker pathway <NUM> to fine-tune placement of the scaling marker <NUM> prior to image capture by the data collection unit <NUM>. In another aspect, the main body <NUM> can comprise a plurality of scaling marker pathways <NUM>, each of the plurality of scaling marker pathways <NUM> corresponding to scaling marker placement for a selected image of the selected anatomical structure. In operation, an operator can selectively position the scaling marker enclosure <NUM> along a selected scaling marker pathway <NUM> corresponding to a selected image to be captured by the data collection unit <NUM>.

In another aspect illustrated in <FIG>, the scaling marker enclosure <NUM> can contain a scaling marker <NUM>. The scaling marker <NUM> can be selectively displaceable about and between the first end and the second end of the scaling marker enclosure <NUM>. The scaling marker pathway <NUM> can comprise a slot <NUM> defined in the main body <NUM>. The scaling marker enclosure <NUM> can have a complementary geometry to and can be receivable in the slot <NUM>. In another aspect, the main body <NUM> can comprise a plurality of slots <NUM>, each of the plurality of slots <NUM> corresponding to scaling marker placement for a selected image of the selected anatomical structure. In operation, an operator can position the scaling marker enclosure <NUM> in a selected slot <NUM> corresponding to scaling marker placement for a selected image to be captured by the data collection unit <NUM>.

In one aspect, the main body <NUM> can comprise a sleeve <NUM>. The sleeve can be adapted to receive the selected anatomical structure. Optionally, the sleeve can be a compression sleeve. In one aspect, the scaling device <NUM> can comprise a sleeve <NUM> and the anatomical registering feature <NUM> can comprise a hole disposed in the sleeve. In one illustrative example, the selected anatomical structure can comprise a knee and the anatomical registering feature <NUM> can comprise a hole for receiving a patella.

In another aspect, the main body <NUM> can comprise a first end <NUM> and an opposed second end <NUM> that can be secured together with a fastener. Optionally, the main body <NUM> can further comprise a strap <NUM> coupled to and extending away from the first end <NUM> and a loop <NUM> coupled to the second end <NUM>. The strap <NUM> can comprise a hook-and-loop fastener or any other suitable fastener type. In operation, the first strap <NUM> can be passed through the loop <NUM> and folded back on itself to bring the hook-and-loop fastener into mating contact and secure the main body to the selected anatomical structure. In one illustrative example, the selected anatomical structure can comprise a knee and the anatomical registering feature <NUM> can comprise a hole for receiving the patella.

In other aspects illustrated in at least <FIG>, the scaling device <NUM> can accommodate variations in either or both of leg size and diameter. In additional or alternative aspects illustrated in at least <FIG>, a single scaling device <NUM> can be used for scaling a variety of different images, such as both femur and tibia images, and images on both the left and right legs.

In another aspect illustrated in <FIG>, the main body <NUM> can comprise a pair of shorts or pants, wherein at least one of the waist and the split of the legs of the pair of shorts or pants comprises the anatomical registering feature <NUM>. The scaling marker pathways <NUM> can be selectively arranged for one or more of pelvic imaging, hip imaging, femoral imaging, and the like. In one aspect, the shorts or pants can be reversible so that one device can accommodate both the left and right side anatomy of a patient.

In another aspect illustrated in <FIG>, the main body <NUM> can comprise an adjustable enclosure <NUM> comprising a base plate member <NUM>, a handle member <NUM>, and two (or more) scaling markers <NUM> coupled to at least the handle member <NUM>. The anatomical registering feature can be a hole <NUM> defined by the adjustable enclosure <NUM> for receiving a leg of a patient. At least the base plate member <NUM> can be laterally expandable to accommodate various patient leg widths. The handle member <NUM> can be slidingly engaged with the base plate member <NUM> and selectively adjustable about and between a first position where the handle member <NUM> is located a first distance from the base plate member <NUM> and a second position where the handle member <NUM> is located a second, greater distance from the base plate member <NUM>. The pathway traveled by the handle member <NUM> between the first position and the second position can define the scaling marker pathway <NUM>. The scaling markers <NUM> can each move with the handle member <NUM> such that they can be fixed relative to each other as the handle member <NUM> moves about and between the first position and second position. The adjustable enclosure can comprise a radiolucent material. The adjustable enclosure <NUM> can have a free state where the base plate member <NUM>, the handle member <NUM>, and the scaling markers <NUM> can be static and an engaged state where the handle member <NUM> and scaling markers <NUM> can move relative to the base plate member <NUM>.

In other aspects illustrated in <FIG>, the present teachings provide for a method, which however is not claimed, for imaging a selected anatomy comprising the steps of: securing the main body with respect to an anatomical registration feature; adjusting a scaling marker about and between a first end and a second end of a scaling marker pathway to fine-tune placement of the scaling marker relative to the selected anatomy; and capturing and scaling an image of the selected anatomy. In one illustrative example, the device shown in any one of <FIG> can be used according to the following exemplary method to obtain images of a knee prior to surgery. The main body <NUM> can be secured around the leg of a patient such that anatomical registering feature <NUM> receives the patella. A lateral X-ray can be planned and the scaling marker <NUM> can be placed along a first scaling marker pathway 110a on the main body corresponding to the anterior side of the knee, ensuring the resulting image will not have the scaling marker <NUM> obscuring important anatomical features of the knee. The data collection unit <NUM> can then capture the lateral image of the knee with the scaling marker <NUM> and use the scaling marker characteristics to scale the image. Optionally, the scaling marker <NUM> can then be removed from the first scaling marker pathway 110a and placed on a second scaling marker pathway 110b corresponding to the lateral side of the knee, again ensuring the scaling marker <NUM> will not obscure important anatomical features of the knee. Again, the data collection unit <NUM> can capture the lateral image of the knee with the scaling marker <NUM> and use the scaling marker characteristics to scale the image.

Claim 1:
A scaling device (<NUM>), comprising:
a main body (<NUM>,<NUM>) having at least one anatomical registering feature (<NUM>,<NUM>) configured to be aligned with a selected anatomical feature, wherein the main body is conformable to the selected anatomical structure, wherein the main body further comprises a scaling marker (<NUM>,<NUM>) and a scaling marker pathway (<NUM>,110a,110b) that is selectively oriented with respect to the anatomical registering feature and facilitates repeatable gross placement of the scaling marker (<NUM>,<NUM>) relative to the selected anatomical structure, wherein the scaling marker pathway has a first end and an opposed second end , and wherein the scaling marker is selectively displaceable along the scaling marker pathway about and between the first end and the second end to enable fine placement of the scaling marker relative to the selected anatomical structure.