| 摘要 |
An implantable medical device (IMD) uses a solid-state sensor for detecting the application of an external magnetic field, the sensor comprises one or more magnetic field responsive microelectromechanical (MEM) switch fabricated in an IC coupled to a switch signal processing circuit of the IC that periodically determines the state of each MEM. The MEM switch comprises a moveable contact suspended over a fixed contact by a suspension member such that the MEM switch contacts are either normally open or normally closed. A ferromagnetic layer is formed on the suspension member, and the suspended contact is attracted or repelled toward or away from the fixed contact. The ferromagnetic layer, the characteristics of the suspension member, and the spacing of the switch contacts may be tailored to make the switch contacts close (or open) in response to a threshold magnetic field strength and/or polarity. A plurality of such magnetically actuated MEM switches are provided to cause the IMD to change operating mode or a parameter value and to enable or effect programming and uplink telemetry functions.
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