Physiological sensor system with automatic authentication and validation by means of a radio frequency identification protocol with an integrated RFID interrogator system
This invention relates to a physiological sensor which acquires pre-programmed data from an electrode or an electrode array using Radio Frequency Identification (RFID) technology. The source of the sensor may be authenticated by means of a wireless interface between an RFID transponder affixed to the electrode array, and an RFID interrogator embedded in the patient interface cable. The criteria for use are then verified to ensure that they are met by the electrode array before beginning signal acquisition. If the criteria are not met, a message is provided to the user via the monitor.
1. An interface cable for connecting electrodes to a physiological monitor comprising:
sockets connectable to an electrode array of at least one electrode,
a RFID interrogator,
a RFID antenna matching circuit,
a RFID antenna,
said RFID interrogator, antenna matching circuit and antenna being incorporated into said patient interface cable.
2. The interface cable of claim 1 further comprising a molded thermoplastic cover positioned around said sockets.
3. The interface cable of claim 1 further comprising a switching power supply, said switching power supply being connected to the RFID interrogator to limit the power consumed by the RFID interrogator.
4. The sensor of claim 3 further comprising a mating receptacle which electrically connects said interface cable to a monitor containing a processor.
5. The sensor system of claim 4 , wherein said processor is located in the monitor.
6. The sensor system of claim 4 , wherein said RFID interrogator is located in the monitor.
7. The sensor system of claim 4 , wherein said antenna matching circuit is located in the monitor.
8. The interface cable of claim 1 further comprising a capacitor bank, said capacitor bank being connected to the RFID interrogator to limit the power consumed by the RFID interrogator.
9. A sensor for acquiring physiological signals comprising:
an interface cable including sockets connectable to an electrode array of at least one electrode, a RFID interrogator, a RFID antenna matching circuit, a RFID antenna, said RFID interrogator, antenna matching circuit and antenna being incorporated into said patient interface cable,
an electrode array of at least one electrode connectable to said sockets,
at least one RFID transponder for storing information,
wherein said at least RFID transponder is affixed to at least one electrode of said electrode array.
10. The sensor of claim 9 wherein said information stored in said RFID transponder includes an electrode array lot code.
11. The sensor of claim 9 wherein said information stored in said RFID transponder includes an electrode array serial number.
12. The sensor of claim 9 wherein said information stored in said RFID transponder includes an electrode array shelf life code.
13. The sensor of claim 9 wherein said information stored in said RFID transponder includes an OEM code identifying the distributor of said electrode array.
14. The sensor of claim 9 wherein said information stored in said RFID transponder includes a usage counter indicating the number of uses remaining.
15. The sensor of claim 9 wherein said information stored in said RFID transponder includes a digital signature for authentication and validation.
16. The sensor of claim 9 further comprising a microprocessor contained within the interface cable for processing data stored in the RFID transponder.
17. The sensor of claim 16 wherein said processor runs software which uses the value of an OEM code to allow or disallow the acquisition of physiological signals from said electrode array.
18. The sensor of claim 16 in which said microprocessor runs software which reformats said information stored in said RFID transponder to ISO 7816 format.
19. The sensor of claim 16 , in which said microprocessor runs authentication software.
20. The sensor of claim 16 in which said microprocessor uses said authentication software to validate a digital signature stored in said RFID transponder, wherein successful validation of said digital signature is required before said sensor array is used for the acquisition of electrophysiological signals.
21. The sensor of claim 9 , additionally comprising a means of monitoring the connection status of said electrode array.
22. The sensor of claim 21 in which said means of monitoring the connection status of the electrode array comprises continuous polling of the RFID transponder IC by the RFID interrogator.
23. The sensor of claim 21 in which said means of monitoring the connection status of the electrode array comprises a analog-to-digital converter which samples the voltage of the antenna matching circuit.
24. The sensor of claim 21 in which said means of monitoring the connection status of the electrode array comprises a voltage comparator which senses the voltage of the antenna matching circuit.