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US 4,543,091 AGranted
X-ray marker device
AssigneeEdward C. Froning
InventorsEdward C. Froning, Gregory S. Graham
Life of this patent
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AssigneeEdward C. Froning
InventorsEdward C. Froning, Gregory S. Graham
Estimating the term…
For pre-operative radiography preparatory to stereotaxic lateral extradural disc puncture (e.g. as disclosed in U.S. Pat. No. 3,941,127) the patient is placed on his side and a radiographic film is exposed from which the surgeon calculates position and angle of needle approach to the disc before the actual operation begins. An X-ray opaque marker device similar to a ruler is located parallel and adjacent to the patient at the level of the midsaggital plane. Markings and numbers on the marker device show on the exposed film. With prolonged X-ray exposure, the image of the marker may be "burned". The present device provides a series of radiopaque shields which may be interposed between the marker and the film to reduce burn-out of the image of the marker on the film. A convenient stand supports and stores the marker and one or more shields so that they may be individually and selectively raised and turned into operative position.
An X-ray marker device comprising a base formed with a rectangular storage depression, a single, round rod extending upward from said base adjacent one longitudinal edge of said depression, a substantially rectangular marker shaped to fit into said depression, said marker having a cylindrical collar fixed thereto, said collar being rotatable relative to said rod and longitudinally slidable along said rod between a storage position with said marker stored in said depression and an operative position, said marker when in operative position being on the side of said rod opposite said depression, and turned 180.degree. relative to its storage position and substantially elevated above said base, said collar having friction means on its interior, the weight of said marker causing said friction means to secure said collar and said marker against movement longitudinally of said rod;
Dependencies are inferred from the claim text.