Patent ID: 7641612

Claim:
A blood loss detection device for a hemodialysis system having a blood intake line, a dialysis machine including a pump, said dialysis machine in communication with said blood intake line, and a blood return line in communication with said dialysis machine, which detection device comprises: a patch having an external boundary edge circumnavigating said patch; a central opening through said patch so that said patch surrounds said central opening, wherein said central opening is within said boundary edge and forms a target for receipt of a return access site and said blood return line so that said opening of said patch surrounds and encloses said target; a slit through said patch extending between said boundary edge and said central opening; a primary circuit loop circumnavigating said central opening terminating at two ends at said slit; an early warning alarm circuit loop circumnavigating said central opening terminating at two ends at said slit; an emergency shut-down circuit loop circumnavigating said central opening terminating at two ends at said slit, said emergency shut-down circuit loop independent from said early warning alarm circuit loop wherein said primary circuit loop, said early warning alarm circuit loop, and said emergency shut-down circuit loop are in a radial plane; and a modular connector connecting said patch to an alarm activated by said early warning alarm circuit loop and to a switch mechanism actuated by said emergency shut-down circuit loop to shut down said dialysis machine and pump wherein said early warning alarm circuit loop is activated by a small blood leak and wherein said emergency shut-down circuit loop is activated by a larger blood loss.