Patent ID: 11860197
Assignee: NXSTAGE MEDICAL, INC.
Field: Measurement (Instruments)
Classification: CPC G  A | IPC A  G

Claim 18:
19. A system for sensing and counteracting leakage current from a patient fluidly connected to a medical device by tubing filled with a conductive fluid, the system comprising:
at least a pair of sensor/transducers, each of the sensor/transducers including
a magnetically conductive core with a centrally located support member configured to receive a length of tubing filled with the conductive fluid, and
at least two electrically conducting coils located at positions that are spaced from the centrally located support member on opposite sides thereof,
wherein the magnetically conductive core comprises a magnetically conductive central branch on which the centrally located support member is disposed in surrounding relationship and a pair of magnetically conductive outer branches with at least one of the electrically conducting coils disposed in surrounding relationship to each of the outer branches, and
wherein the magnetically conductive core forms two magnetic sub-circuits with the magnetically conductive central branch forming a common portion of each of the two magnetic sub-circuits and with each of the magnetically conductive outer branches forming a portion of one of the two magnetic sub-circuits,
wherein said at least a pair of sensor/transducers are disposed on the tubing with the tubing supported by the centrally located support member and coiled around the magnetically conductive central branch of each sensor/transducer, with a first one of the sensor/transducers arranged to detect leakage current flowing within the conductive fluid and a second one of the sensor/transducers arranged to induce current within the conductive fluid to counteract the leakage current when voltage is applied to the electrically conducting coils of the second sensor/transducer.