Nikola Tesla film in his laboratory in previous experiments (later identified as ""Roentgen rays"" or "X-Rays"). His early experiments were with Crookes tubes, a cold cathode electrical discharge tube. Tesla may have inadvertently captured an X-ray image—predating, by a few weeks, Wilhelm Röntgen's December 1895 announcement of the discovery of X-rays when he tried to photograph Mark Twain illuminated by a Geissler tube, an earlier type of gas discharge tube. The only thing captured in the image was the metal locking screw on the camera lens. In March 1896, after hearing of Wilhelm Röntgen's discovery of X-ray and X-ray imaging (radiography), Tesla
Roentgen stereophotogrammetry are accurately measured and the three-dimensional position of the markers is reconstructed using software. The change in the position (translation and rotation) of the prosthesis markers relative to the bone markers is then determined. The reported accuracy of RSA ranges between 0.05 and 0.5 mm for translations and between 0.15˚ and 1.15˚ for rotations (95% confidence interval). New RSA techniques that avoid the need for attaching markers to the prosthesis have been introduced. Roentgen stereophotogrammetry Roentgen stereophotogrammetry (RSA) is a highly accurate technique for the assessment of three-dimensional migration and micromotion of a joint replacement prosthesis relative to the bone