Donation of an organ from a living person to save another's life, where the donor's health will not appreciably suffer,[1] is permitted and encouraged in Jewish law.
[3] In judging cases for organ donation, rabbis apply a range of Jewish principles and consider precedents concerning the donor.
If the accepted definition if death is "incorrect", removing a heart from a donor who was established dead under the "wrong" criteria is considered tantamount to murder.
[4] According to some, Jewish law defines death as a state of complete and irreversible cessation of cardiorespiratory function followed by a minimum of five minutes' waiting during which it is not restored (period of time depends on custom).
[5] Regarding the point at which a person is considered dead in the case of brain-stem death with a ventilator machine causing heartbeat, a definitive consensus from halachic authorities has not been reached as of today.
However increasing numbers of orthodox authorities accept brain stem death with various stringencies, enabling surgeons to take full advantage of modern medical technology in transplantations of organs from the deceased.
Jewish law forbids touching the body of a goses for fear that any sudden movement may accelerate the time of death.
[1] Artificial heart transplants are not permissible according to Jewish law due to low success rates and the serious medical complications involved.
Other rabbis allow it as an act of piety, and others believe it is an obligation not to violate a precept, "Thou shall not stand idly by the blood of thy fellow man.