Dual power supply switching circuitry for use in a closed system
Optimal power switching circuitry for use in a closed system such as a TET system including an internal device separated from an external device by a boundary. The internal and external devices being powered by separate power sources. During telemetric communication from the external device to the internal device an external RF energy source is produced. If the power supplied by the external RF energy source produced during communication from the external device to the internal device exceeds that required for powering of the internal device, then the power switching circuitry cuts off power to the internal power source and instead draws power from the external RF energy source thereby conserving power consumed from the internal power source. The power switching circuitry may be implemented using either passive components (e.g., diodes) or active components (e.g., an analog switch).
1. A closed system having dual power supply switching circuitry, comprising:
an implantable medical device disposed interior of a boundary;
an internal power source for powering the implantable medical device:
an external device separated from the implantable medical device by and disposed exterior to the boundary, the external device being in telemetric communication with the implantable medical device and generating an external RF energy source during telemetric communication with the implantable medical device between a primary coil associated with the external device and a secondary coil associated with the implantable medical device; and
a first diode electrically connected to draw power from the external RF energy source, and a second diode electrically connected to draw power from the internal power source, the first and second diodes are electrically coupled between the secondary coil and the internal power source for switching from the internal power source to the external RF energy source during communication from the external device to the implantable medical device only when power supplied by the external RI energy source exceeds that required for powering the implantable medical device;
wherein the first and second diodes are electrically coupled to a common voltage supply line node; and wherein the first diode is electrically connected between the common voltage supply line node and the external RF energy source, while the second diode is electrically connected between the common supply line node and the internal power source; and the closed system further comprising a capacitor electrically connected directly to an output of each of the first and second diodes to provide power to the implantable medical device while switching the power supply.
2. A method switching of a power supply in a closed system including an internal power source used to power an implantable medical device separated from an external device by a boundary, comprising the steps of:
generating an external RF energy source during telemetric communication between a primary coil associated with the external device and a secondary coil associated with the implantable medical device; and
during communication from the external device to the implantable medical device only when power supplied by the external RF energy source exceeds that required for powering the implantable medical device, switching from the internal power source to the external RF energy source using a first diode electrically connected to draw power from the external RF energy source, and a second diode electrically connected to draw power from the internal power source the first and second diodes are electrically coupled between the secondary coil and the internal power source for switching from the internal power source to the external RF energy source during communication from the external device to the implantable medical device only when power supplied by the external RF energy source exceeds that required for powering the implantable medical device;
wherein the first and second diodes are electrically coupled to a common voltage supply line node; and wherein the first diode is electrically connected between the common voltage supply line node and the external RF energy source, while the second diode is electrically connected between the common supply line node and the internal power source; and the closed system further comprising a capacitor electrically connected directly to an output of each of the first and second diodes to provide power to the implantable medical device while switching the power supply.