Patent ID: 8509913
Filing Date: 2013-08-13
Classification: A61B,A61N,G01R

Abstract:
1. An active implantable medical device (AIMD), comprising: a) a conductive device housing for the AIMD, the housing containing tissue-stimulating or biological-sensing circuits connected to a first electrical switch point; b) a second electrical switch point that is electrically connectable to an electrode configured for tissue stimulating or biological-sensing; c) an energy dissipating surface provided by the device housing as a third electrical point; d) at least one diversion circuit electrically connecting between a fourth electrical switch point and the third electrical point at the energy dissipating surface; and e) at least one switch that is actuatable in response to a magnetic resonance B f) wherein with the switch electrically connecting the second electrical switch point to the fourth electrical switch point at the diversion circuit and at relatively high frequencies attendant to the AIMD being subjected to an MRI RF pulse field, the diversion circuit acts as a relatively low impedance circuit from the fourth electrical switch point to the third electrical point at the energy dissipating surface, and g) wherein with the switch electrically connecting the second electrical switch point to the fourth electrical switch point at the diversion circuit and at relatively low frequencies attendant to the AMID being subjected to an MRI gradient field, the diversion circuit acts as a relatively high impedance circuit between the fourth electrical switch point and the third electrical point at the energy dissipating surface.