Patent GB-1282911-A (GB)
Title: Image storage, reproduction and comparison system
Inventor: SIEDBAND M P
IPC: H05G1/64
Filed: 1969-08-06
Abstract: 1282911 X-ray-television system CGR MEDICAL CORP 6 Aug 1969 [22 Aug 1968 39334/69 Heading H4F An X-ray picture is recorded frame by frame on respective closed loops of a magnetic recording medium so that the following modes of operation become possible:- (a) Stop action mode-in which a particular X-ray picture can be recorded for future viewing on a CRT after the irradiation has ceased. (b) Contact enhancement-for use in comparing a normal X-ray picture with one due for example to a barium meal injection X-ray picture. (c) Energy comparison-for use in comparing a normal high energy X-ray picture with a low energy X-ray picture, the latter normally showing up some specialized tissue. (d) Intermittent slide-for use in automatically intermittently activating an X-ray machine and showing pictures in real time. Details of these modes follow:- Stop Action Mode Switch 138 is set to N, this sets switches 108/110. Foot switch 64 is pressed, feeding A.C. (40) to X-ray generator 10, via 65. The X-ray picture is detected by TV camera 16 and is viewed at monitor 68 or recorded in means 72 or 74. To record an X-ray picture on a track of disc 22, button 76 is depressed, activating means 82. The thus set 1st bistable 84 is reset by the next frame sync. pulse VF, all the sync. pulses being recorded on the outer track of the disc. The reset, resets 2nd bistable 86 and activates gate 88 which remains open for one frame to pass the X-ray picture video signal to the disc. Sync. signals are removed from the video signal at 90. So that the X-ray generator remains activated during the recording period even if the switch 64 is released, set pulse from bistable 98 lasting for the record period holds coupling circuit 65 open to 40. For recording one frame only, switch 64 need not be pressed. The X-ray generator is activated by pushing record button 76, producing a signal 78. Signal 78 is also used via delay 104 to give the X-ray generator and TV camera time to warm up before the recording is made. When playing back, switches 64 and 76 are not depressed so that the recorded signal from head 32 passes through gate 88, switches 108, 110, amplifier 1124 sync. restorer 118 to monitor 68 on recorder 72/74. Contrast Enhancement Switch 138 and switches 108, 110 set to C. A previously recorded frame on track 26 passes via means 88, 102, 130 (invertor), to end 132 of potentiometer 128. The real time (barium meal) frame passes via stripper 90 to the other end 126 of the potentiometer. The difference (contrast) between the two frames is picked up at terminal 134 and passes to display/recorders 68, 72, 74 via means 114, 118, 122. Potentiometer 114, ganged to 128 controls the amount of cancellation from one frame to the next. The difference signal can be recorded on track 28 by depressing button 140. This recorded signal is viewed on monitor 160. Energy Comparison After a normal energy X-ray picture has been recorded, a lower energy X-ray picture can be shown by setting 138 to #KV, whereby signal on 67 causes a reduced voltage to be applied to generator 10. Lower energy picture is compared with the normal picture in the same manner as used in the contrast enhancement mode, i.e. switches 110, 108 are kept in the C position. The difference picture can be displayed or recorded. Intermittent Slide Switch 138 is set in the S position and control 174 is set to give gap between 1 frame activations of X-ray generator 10, e.g. 1 frame every 15 seconds is shown and one pulse appears on 176 every 15 seconds. During a gap the last recorded picture is played back. Warm up time (1/30 sec.) for the X-ray generator and TV camera is given by delay 104.