Abstract: Techniques are disclosed for tuning a frequency at which an external device transcutaneously transfers energy. The transferred energy may be used to charge a rechargeable power source of an implantable medical device (IMD) and/or to power the IMD directly. One embodiment relates to a charging system that may comprise a circuit to drive a primary coil of an external device at a drive frequency and a control circuit to tune the drive frequency based on a characteristic of a monitored signal that is associated with the primary coil. The characteristic is not present when the primary coil is being driven at a resonant frequency of the system. In a specific example, the characteristic comprises a stub pulse and the control circuit is configured to tune the drive frequency based on at least one of a relative timing and a width of the stub pulse.

Abstract: Techniques adapted for use with recharging a rechargeable power source of an implantable device. One aspect relates to providing a flexible primary coil that can be transcutaneously coupled to a secondary coil of the implantable device. Multiple adjacent turns of the coil are grouped via lacing to form bundles. The bundles have at least one dimension that is selected to be a same size as a predetermined thickness of the coil. In one embodiment, the dimension is a diameter of the bundle. In another embodiment, the dimension is at least one of a length or width of the bundle. Insulating overmolding may be provided over the coil. In one embodiment, the resulting antenna structure is bidirectional such that substantially the same performance characteristics are obtained during recharge regardless of which of two major surfaces of the antenna is placed in proximity to the patient.

Abstract: In general, the techniques of this disclosure are directed to communication between an implantable medical device (IMD) and an external device. In some examples, the external device transmits a signal that includes a communication key. One or more sensors of the IMD sense the signal that includes the communication key, and the IMD uses the communication key for coding the communication between the IMD and the external device. The one or more sensors that sensed the signal may also sense one or more patient characteristics.

Abstract: Techniques are disclosed for tuning a frequency at which an external device transcutaneously transfers energy. The transferred energy may be used to charge a rechargeable power source of an implantable medical device (IMD) and/or to power the IMD directly. One embodiment relates to a charging system that may comprise a circuit to drive a primary coil of an external device at a drive frequency and a control circuit to tune the drive frequency based on a characteristic of a monitored signal that is associated with the primary coil. The characteristic is not present when the primary coil is being driven at a resonant frequency of the system. In a specific example, the characteristic comprises a stub pulse and the control circuit is configured to tune the drive frequency based on at least one of a relative timing and a width of the stub pulse.

Abstract: Techniques adapted for use with recharging a rechargeable power source of an implantable device. One aspect relates to providing a flexible primary coil that can be transcutaneously coupled to a secondary coil of the implantable device. Multiple adjacent turns of the coil are grouped via lacing to form bundles. The bundles have at least one dimension that is selected to be a same size as a predetermined thickness of the coil. In one embodiment, the dimension is a diameter of the bundle. In another embodiment, the dimension is at least one of a length or width of the bundle. Insulating overmolding may be provided over the coil. In one embodiment, the resulting antenna structure is bidirectional such that substantially the same performance characteristics are obtained during recharge regardless of which of two major surfaces of the antenna is placed in proximity to the patient.