A voucher is a bond of the redeemable transaction type which is worth a certain monetary value and which may be spent only for specific reasons or on specific goods.
In 1985 a robot, the Unimation Puma 200, was used to place a needle for a brain biopsy using CT guidance. In 1992, the PROBOT, developed at Imperial College London, was used to perform prostatic surgery by Dr. Senthil Nathan at Guy's and St Thomas' Hospital, London. This was the first pure robotic surgery in the world.
Black surgeon performs the first sucessful open-heart surgery in America. On this date in 1893, the first successful American open-heart surgery was performed by a Black surgeon, Dr. Daniel Hale Williams. Dr. Daniel Williams completed the operation on a young man named James Cornish.