Implantable device monitoring arrangement and method

DETAILED DESCRIPTION We claim: 1.
A monitoring arrangement for monitoring and controlling a device implantable in a human body comprising a secondary coil which is encapsulated in a material which does not substantially attenuate magnetic flux and is locatable internal to a human body wherein the secondary coil is connected to the device, a primary coil locatable external to a human body which transmits electromagnetic energy by electromagnetic carrier waves to the secondary coil, thereby inducing electric current in the secondary coil for supplying power to the device, and an electrical circuit locatable external to a human body for modulating the electromagnetic carrier waves transmitted to the secondary coil, the device comprising a detection circuit for detecting signals induced by modulation of the electromagnetic carrier waves transmitted to in the secondary coil.
2.
A monitoring arrangement according to claim 1 wherein the electrical circuit locatable external to a human body comprises a communication interface for receiving instructions from a remote location for modulating the electromagnetic carrier waves transmitted to the secondary coil by the primary coil.
3.
A monitoring arrangement according to claim 2 wherein the external electrical circuit further comprises means for detecting signals from the device and transmitting the signals to a remote monitoring system.
4.
A monitoring arrangement according to claim 3 wherein the remote monitoring system comprises means for acquiring, recording and evaluating data from the external electrical circuit.
5.
A monitoring arrangement according to claim 3 wherein the external electrical circuit communicates with the remote monitoring system through a modem.
6.
A monitoring arrangement according to claim 1 wherein the external electrical circuit comprises a variable frequency oscillator which modulates the frequency of the electromagnetic carrier waves.
7.
A monitoring arrangement according to claim 1 including magnetic means connected to the second coil to improve electromagnetic coupling of the external primary coil and internal secondary coil