METHOD AND APPARATUS FOR DETERMINING THE POSITION OF A TARGET RELATIVE TO A REFERENCE OF KNOWN CO-ORDINATES AND WITHOUT A PRIORI KNOWL-EDGE OF THE POSITION OF A SOURCE OF RADIATION

摘要

The invention relates to a method and to apparatus for determining the exact position of a target (c) relative to a reference (O) of known co-ordinates. The apparatus comprises a source of radiation (30) for forming an image of a target (c), which image is received by a receiver device (24) situated beyond the target. A mask-forming device (40) is interposed between the receiver device and the source of radiation, the mask-forming device including at least one localization means (R1, R2) of known position relative to a reference point and suitable for forming an image in said image-forming radiation, means are also provided for displacing the radiaton source in three dimensions, at least between two different angular positions (S1, S2), thereby displacing the co-ordinates of two different images of the target obtained from the two different angular positions of the source. The invention makes it possible to determine the exact position of a target with a very high degree of precision using a method which is simple and which limits the radiation dose. The target may be a cell or a stone or a bone to be treated.