An implantable medical device is configured determine a numerical value of a variable that is monitored by the implantable medical device and convert the numerical value to a data sequence of modulated electrical stimulation rate intervals. The implantable medical device delivers electrical stimulation pulses according to the data sequence of modulated stimulation rate intervals to cause a modulated rate of activation of excitable tissue of a patient corresponding to the modulated stimulation rate intervals. The modulated rate of activation is detectable by a rate monitor for demodulation to the numerical value of the monitored variable data value. In some examples, the implantable medical device is a pacemaker delivering cardiac pacing pulses according to modulated pacing rate intervals to cause a modulated heart rate of the patient detectable by a heart rate monitor for demodulation to the numerical value of the monitored variable.

An implantable medical device is configured determine a numerical value of a variable that is monitored by the implantable medical device and convert the numerical value to a data sequence of modulated electrical stimulation rate intervals. The implantable medical device delivers electrical stimulation pulses according to the data sequence of modulated stimulation rate intervals to cause a modulated rate of activation of excitable tissue of a patient corresponding to the modulated stimulation rate intervals. The modulated rate of activation is detectable by a rate monitor for demodulation to the numerical value of the monitored variable data value. In some examples, the implantable medical device is a pacemaker delivering cardiac pacing pulses according to modulated pacing rate intervals to cause a modulated heart rate of the patient detectable by a heart rate monitor for demodulation to the numerical value of the monitored variable.

The disclosed techniques allow for externalizing errors from an implantable medical device using the device's charging coil, for receipt at an external charger or other external device. Transmission of errors in this manner is particularly useful when telemetry of error codes through a traditional telemetry coil in the implant is not possible, for example, because the error experienced is so fundamental as to preclude use of such traditional means. By externalizing the error via the charging coil, and though the use of robust error modulation circuitry in the implant designed to be generally insensitive to fundamental errors, the external charger can be consulted to understand the failure mode involved, and to take appropriate action.

Synchronized stimulation of cardiac tissue can be implemented by implanting two or more rectifier-based AM receivers into different positions within a subject's heart. Each receiver is tuned to a different frequency, and generates an output signal that is capable of stimulating cardiac tissue when a signal at the corresponding tuned frequency arrives at the receiver. An AM transmitter can activate any given one of the receivers by transmitting a signal into the subject's body at the proper frequency. A controller controls the transmitter by commanding the transmitter to transmit pulses of AC at different frequencies at different times, so that when those pulses are received by the correspondingly-tuned receivers, each of the receivers will generate respective output signals that stimulate respective parts of the heart at respective times to promote improved cardiac performance.

An advertising algorithm is disclosed which operates in an Implantable Medical Device (IMD) to adjust an interval at which the IMD will transmit advertising data packets to an external device able to connect with the IMD. When a communication session between the IMD and an external device is terminated, the advertising algorithm will issue advertising data packets at a higher rate for a set duration. This will allow the external device to connect more quickly with the IMD in a next communication session. After the set duration, when it may be assumed that the external device is less likely to connect with the IMD, the algorithm reduces that rate at which advertising data packets are issued, which saves power in the IMD.

Methods and systems for optimizing invasive and noninvasive brain stimulation are described herein. In a particular embodiment, methods and systems for a combinatorial, iterative approach to modify behavior are presented wherein deep brain stimulation (DBS) and other brain stimulation therapies are implemented in combination with monitoring the brain activity of an individual to optimize the effectiveness of the combinatorial approach to modify behavior. Methods described herein are iterative and systems described herein are utilized in iterative fashion. In a particular embodiment, modifying behavior provides a therapy for an individual in need thereof.

An implantable medical device (IMD) has a housing enclosing an electronic circuit. The housing includes a first housing portion, a second housing portion and a joint coupling the first housing portion to the second housing portion. A polymer seal is positioned in the joint in various embodiments. Other embodiments of an IMD housing are disclosed.

Controlling the interaction between an external device and an implanted device, including a method of controlling interaction between an external device and an implanted device, the method including at least the steps of: establishing communications between the implanted device and the external device; the external device determining an identification of the implant and comparing the identification with identifications in a stored list; if the device matches one of said identifications, then using a corresponding set of operating parameters to interact with said implant; and otherwise, not interacting with said device.

The disclosed techniques allow for externalizing errors from an implantable medical device using the device's charging coil, for receipt at an external charger or other external device. Transmission of errors in this manner is particularly useful when telemetry of error codes through a traditional telemetry coil in the implant is not possible, for example, because the error experienced is so fundamental as to preclude use of such traditional means. By externalizing the error via the charging coil, and though the use of robust error modulation circuitry in the implant designed to be generally insensitive to fundamental errors, the external charger can be consulted to understand the failure mode involved, and to take appropriate action.

The implant comprises a tubular body housing an energy harvesting module adapted to convert external stresses applied to the implant into electrical energy, and a rechargeable battery adapted to be charged by the energy harvesting module. During the storage, an external source physically separated from the implant is coupled to the implant rechargeable battery to maintain a minimum battery charge level. An interface circuit of the implant couples surface electrodes to the battery, with switching between: i) a transport and storage configuration where the electrodes are connected to the external source to receive from the latter a battery charging energy and/or to exchange communication signals with the outside through the wire link of the coupling; and ii) a functional configuration in which the surface electrodes are decoupled from the external source after the implant has been implanted. At least one of the implant surface electrodes is an auxiliary electrode that is not a cardiac potential detection/pacing electrode. In the transport and storage configuration, the interface circuit couple the auxiliary electrode to the implant rechargeable battery, and in the functional configuration, the interface circuit decouples the auxiliary electrode from the implant rechargeable battery and put the auxiliary electrode to a floating potential.