Active EMI shielding for protection of medical instruments
View Patent ↗An active EMI shield for protecting medical instruments from mobile RF emitters uses RFID tags and tag readers to facilitate identification of an RF emitter entering the EMI shield. Clinicians and mobile RF emitters are tagged with RFIDs that indicate their identity, and possibly RF power level. Medical instruments are either tagged with RFIDs that indicate their identity and susceptibility to EMI, or equipped with RFID readers/EMI sensors. The proximity of the RF emitter relative to the medical instrument in terms of power density can then be determined by either position-sensitive RFID readers or the EMI sensors affixed to the medical instruments. The shield is executed by signaling to the tagged RF emitter when it reaches a predetermined proximity relative to the medical instrument.
1. A system which protects a protected device from a mobile device which emits radio frequency energy, the system comprising:
a radio frequency identification tag which is affixed to a person before the person enters a predefined area with the mobile emitter device, the radio frequency identification tag configured with data which uniquely identifies a the mobile emitter device; and
a radio frequency identification reader associated with a the protected device, the radio frequency identification reader being associated with first logic which measures electrical proximity, in terms of incident power by direct measurement of radio frequency energy, of the mobile emitter device relative to the protected device, the radio frequency identification reader further being associated with second logic which identifies the mobile emitter from the data with which the radio frequency identification tag is configured, and third logic which prompts the person to reduce the radio frequency energy emitted by the mobile emitter device once the mobile emitter device is measured to be within a predetermined proximity relative to the protected device;
wherein the radio frequency identification reader is disposed at a fixed position which is distant from the protected device;
wherein the radio frequency identification reader is position-sensitive, and including fourth logic which determines the radio frequency energy level emitted by the mobile emitter device and the relative position of the mobile emitter device with respect to the protected device from the radio frequency identification tag associated with the mobile emitter device and a radio frequency identification tag associated with the protected device.
2. The system of claim 1 , wherein the radio frequency identification reader is disposed proximate to the protected device.
3. The system of claim 2 , in which the first logic, which measures proximity of the mobile emitter device relative to the protected device, further includes an electromagnetic interference sensor disposed proximate to the protected device.
4. The system of claim 3 , in which the third logic, in response to signaling from the electromagnetic interference sensor and radio frequency identification reader, prompts manual reduction of radio frequency energy emitted by the mobile emitter device by communicating with an operator of the mobile emitter device.
5. The system of claim 1 , wherein the radio frequency identification tag includes an address at which the mobile emitter device is reachable via network communications.
6. The system of claim 1 , in which the first logic, which measures proximity of the mobile emitter device relative to the protected device, further includes a mobile electromagnetic interference sensor disposed proximate to the protected device.
7. A method comprising the steps of:
configuring a radio frequency identification tag with data which uniquely identifies a mobile emitter device;
affixing the radio frequency identification tag to a person before the person enters a predefined area with the mobile emitter device;
determining electrical proximity of the mobile emitter device relative to a protected device in terms of incident power by direct measurement of radio frequency energy from the mobile emitter device on the protected device;
identifying the mobile emitter device by reading the data with a radio frequency identification reader associated with the protected device; and
prompting the person to reduce the radio frequency energy emitted by the mobile emitter device once the mobile emitter device is measured to be within a predetermined proximity relative to the protected device;
employing a radio frequency identification reader disposed at a fixed position which is distant from the protected device to identify the mobile emitter device;
employing a position-sensitive radio frequency identification reader and logic to identify the radio frequency energy level emitted by the mobile emitter device as indicated by the radio frequency identification tag associated with the mobile emitter device, and the relative position of the mobile emitter device with respect to the protected device from the radio frequency identification tag associated with the mobile emitter device and a radio frequency identification tag associated with the protected device.
8. The method of claim 7 , including the further step of employing the radio frequency identification reader disposed proximate to the protected device to identify the mobile emitter device.
9. The method of claim 8 , including the further step of employing an electromagnetic interference sensor disposed proximate to the protected device to determine electrical proximity of the mobile emitter device.
10. The method of claim 9 , including the further step of prompting, in response to signaling from the electromagnetic interference sensor and radio frequency identification reader, manual reduction of radio frequency energy emitted by the mobile emitter device by communicating with an operator of the mobile emitter device.
11. The method of claim 7 , including the further step of employing the radio frequency identification tag associated with the mobile emitter device and the reader to read the data to determine an address at which the mobile emitter is reachable via network communications in order to prompt reduction of radio frequency energy emitted by the mobile emitter device at a predetermined proximity relative to the protected device.
12. The method of claim 7 , including the further step of employing a mobile electromagnetic interference sensor disposed proximate to the protected device to determine proximity of the mobile emitter device.