Mistaken-organ medical operations occur, on the average, once every 30,000 times - one time too many for the patient who has undergone that particular statistical improbability. To avoid this, Dr. Arik Kahane of Assuta Hospital in Tel Aviv has developed a tattoo patch that will make perfectly clear which organ is to be operated on.

Dr. Kahane, the deputy director of Asuta, also heads the hospital's risk-management unit. Participating with him in developing the tattoo idea were Dr. Michal Gindi of Maccabi Health Services and the PMI company. The tattoo is about to be introduced into the 11 Assuta Medical Centers around the country.

When a leg, hand, lung, kidney or other paired organ is to be operated on, confusion often develops as to which side of the body requires the treatment. The tattoo is provided to patients several days before their operations, and with the help of medical personnel, they are to paste it onto the correct organ or side of the body.

The round sticker, made in Israel, is colored blue and reads, "Operate Here." After approximately a week, the tattoo rubs off on its own.

Former Olympic silver judo medalist Yael Arad, head of the PMI trademark-toy company, said, "We were happy to utilize our knowledge and experience to contribute to such an important objective. We are proud to be a part of this project."