Patent Application
20080058900
The above and other aspects, features and advantages of the present invention will be more apparent from the following more particular description thereof, presented in conjunction with the following drawings wherein:
The following description is of the best mode presently contemplated for carrying out the invention. This description is not to be taken in a limiting sense, but is made merely for the purpose of describing the general principles of the invention. The scope of the invention should be determined with reference to the claims.
In
Patient device 10 is a patient device comprising—among other features of no particular interest for the present invention—a patient device transceiver eTRX, connected to an antenna 20 and to a patient device control unit eCTRL. Control unit eCTRL is connected to a timer 22 and to a patient device memory eMEM. Memory eMEM comprises program or instruction data defining an assignment procedure to be carried out by the control unit eCTRL and the patient device during pairing of patient device 10 to an implant. Memory eMEM also comprises dedicated address space for storing an implant identification code IID.
Control unit eCTRL further is connected to a patient device read only memory eROM comprising the patient devices identification code EID (external device ID).
The implant also comprises a memory iMEM, that preferably is a read only memory ROM for storing an implant identification code IID, a control unit iCTRL connected to the implant's memory iMEM and a transceiver iTRX for bidirectional data communication with the patient device 10.
The tranceiver eTRX of the patient device and of the implant iTRX are both adapted to operate in the MICS band, a wireless communication frequency band reserved for medical implant communications services.
A real world environment may comprise a plurality of patient devices and implants. Therefore, any patient device in such environment shall be assigned to its specific single implant or to no implant at all. Assigning a patient device to an implant is called pairing for the purpose of this description.
Patient device 10 may be in different states of pairing. Patient device 10 may be unpaired, can be soft paired or can be permanently paired (hard paired) to a specific implant. Soft pairing of a patient device to an implant results from automatic pairing, whereas hard pairing of a patient device to an implant results from manual pairing, e.g. via programmer 14.
When in its soft paired state, patient device 10 will return to its unpaired state if for a predetermined period of time no data communication has occurred with the implant that patient device 10 is paired to. For a hard paired patient device, no such period of time is applicable, thus a hard paired patient device is permanently paired to a specific implant.
When patient device 10 is in its unpaired state, patient device 10 also is in a search mode wherein patient device 10 carries out a protocol for automatic pairing. As long as patient device 10 is paired to its specific implant, patient device 10 may be either in a wait mode as long as no data communication is going on with the implant patient device 10 is assigned (paired) to, or in a communication mode during data communication between patient device 10 and the implant patient device 10 is paired to.
As long as patient device 10 is unpaired and therefore is in its search mode, control unit eCTRL causes the patient devices transceiver eTRX to periodically scan the MICS band in order to determine a least used channel. This is called “listen before talk”. Thereafter, patient device 10 will use the least used channel to send out a data packet containing the patient device's identification code EID and an unspecific implant identification code IID as is stored in memory eMEM. Since, when in its search mode patient device 10 is in its unpaired state, no or an unspecific implant identification code is stored in the memory eMEM. In the data packet, an origin identifier bit is set in order to mark the data packet as originating from a patient device.
An implant like implant 12 scanning all channels of the MICS bend eventually may receive a data packet originating from patient device 10. If the data packet contains a specific implant identification code IID that does not correspond to the receiving implant's implant identification code IID, then the receiving implant will not respond to such data packet. On the other hand, if the data packet received by the implant contains an unspecific implant identification code IID (e.g. IID=0), the implant will respond to the data packet by sending out a data packet containing the patient device identification code EID as received with the incoming data packet, its implant identification code IID and a origin identifier bit set as to mark a data packet originating from an implant.
If patient device 10 receives such data packet originating from an implant containing the patient device's own identification code EID, such data packet causes patient device 10 to enter its tentatively paired mode and to store the implant identification code IID received with the data package in memory eMEM.
Patient device 10 thereupon will send out a further data packet with its own identification code EID being the specific patient device identification code as stored in patient device's eROM and the origin identifier bit set to “patient device”. Thereafter, patient device 10 will wait for a predetermined first period of time for a response data packet from the specific implant patient device 10 is tentatively paired to. If during the predetermined period of time a response data packet is received from the implant the patient device is tentatively paired to, and the response data packet contains the patient device's own identification code, then patient device 10 will enter its soft paired state.
The patient device will stay in its soft paired state as long as a data communication periodically occurs with the implant to which the patient device is paired, and as long as no manual reset of the patient device to its unpaired state occurs.
If for another predetermined period of time, being longer than the first period of time that the patient device will wait until leaving its tentatively paired state no data communication between the patient device and the implant it is paired to occurs, the soft paired state is cancelled and the patient device returns into its unpaired state. This is controlled by timer and control unit eCTRL, and is performed by storing an unspecific implant identification code IID, e.g. IID=0, into memory eMEM of patient device 10.
At any time patient device 10 may be manually reset by pressing reset button RESET, or via other means, e.g., a physician, programmer or via the internet.
For further details of the patient device's behavior with respect to pairing please refer to the state diagram in
Although an exemplary embodiment of the present invention has been shown and described, it should be apparent to those of ordinary skill that a number of changes and modifications to the invention may be made without departing from the spirit and scope of the invention. This invention can readily be adapted to such devices by following the present teachings. All such changes, modifications and alterations should therefore be recognized as falling within the scope of the present invention.
