Power saving communication techniques for communicating in a medical device system. One example medical device system may be for delivering electrical stimulation therapy to a heart of a patient, and may include a first implantable medical device implanted in a first chamber of the heart and configured to determine one or more parameters, a medical device physically spaced from and communicatively coupled to the first implantable medical device, the medical device configured to deliver electrical stimulation therapy to the heart of the patient, wherein the first implantable medical device is further configured to: compare a value of a first determined parameter to a first threshold; if the value of the first determined parameter passed the first threshold, communicate a first indication to the medical device; and if the value of the first determined parameter has not passed the first threshold, not communicating the first indication to the medical device.

Techniques for retrieving information from an implantable medical device (IMD) having a depleted internal energy source such as a non-rechargeable battery are disclosed. The IMD is powered by and communicates with an external interrogation device to access a memory location of the IMD and for transfer of the information in the memory location to the external interrogation device subsequent to depletion of the internal energy source. In an embodiment, the memory location is included in a non-volatile memory component of the IMD to maintain the information stored in the memory component.

A method and apparatus for determining estimated remaining longevity for an implantable stimulator. The device employs pre-calculated numbers of days for various combinations conditions of device usage parameters to determine remaining device longevity based upon identified actual conditions of device usage and employs the determined longevity to change longevity indicator states in the device. While between longevity state changes, the device the identified conditions of device usage and adjusts the determined longevity if the conditions of use change significantly. The indicator states may correspond to one or more of Recommended Replacement Time (RRT), Elective Replacement Indicator (ERI) or End of Service (EOS).

A leadless cardiac pacing system includes first and second leadless pacing seeds configured to deliver pacing therapy to a first and second location in a patient, respectively. The second seed includes an electrode, a therapy circuit configured to provide electrostimulation energy to the electrode, a communications component, and a power source. The second seed also includes a power manager configured to detect an end-of-life condition associated with the seed and, in response to detecting the end-of-life condition, to communicate a signal that causes the first seed to change from a first operational state to a second operational state, in which the first seed implements one or more operational parameters configured to adapt to a change in an output from the second seed resulting from the second seed entering the end-of-life condition.

An improved architecture for an implantable medical device using a primary battery is disclosed which reduces the circumstances in which the voltage of the primary battery is boosted, and hence reduces the power draw in the implant. The architecture includes a boost converter for selectively boosting the voltage of the primary battery and for supplying that boosted voltage to certain of the circuit blocks, including digital circuitry, analog circuitry, and memory. However, the boost converter is only used to boost the battery voltage when its magnitude is below a threshold; if above the threshold, the battery voltage is passed to the circuit blocks without boosting. Additionally, some circuitry capable of operation even at low battery voltagesincluding the telemetry tank circuitry and the compliance voltage generatorreceives the battery voltage directly without boosting, and without regard to the current magnitude of the battery voltage.

An implantable medical device includes circuitry for generating and delivering electrical stimulation therapy. A power source is included in the implantable medical device for storage of the energy for the stimulation therapy. Techniques and circuits are provided for minimizing energy losses associated with the storage of the stimulation therapy energy. The implantable medical device circuitry includes charging circuitry that is operated in at least a first mode and a second mode, such that the charging circuit is operable in one of the at least first and second modes based on whether an intrinsic cardiac event is detected. The charging circuit is operable to withhold charging the output capacitor in the first mode until a given cardiac cycle elapses without a sensed intrinsic cardiac event.

An implantable neural stimulator method for modulating excitable tissue in a patient including: implanting a neural stimulator within the body of the patient such that one or more electrodes of the neural stimulator are positioned at a target site adjacent to or near excitable tissue; generating an input signal with a controller module located outside of, and spaced away from, the patient's body; transmitting the input signal to the neural stimulator through electrical radiative coupling; converting the input signal to electrical pulses within the neural stimulator; and applying the electrical pulses to the excitable tissue sufficient to modulate said excitable tissue.

An implantable neural stimulator method for modulating excitable tissue in a patient including: implanting a neural stimulator within the body of the patient such that one or more electrodes of the neural stimulator are positioned at a target site adjacent to or near excitable tissue; generating an input signal with a controller module located outside of, and spaced away from, the patient's body; transmitting the input signal to the neural stimulator through electrical radiative coupling; converting the input signal to electrical pulses within the neural stimulator; and applying the electrical pulses to the excitable tissue sufficient to modulate said excitable tissue.

Implanted pulse generators with reduced power consumption via signal strength-duration characteristics, and associated systems and methods are disclosed. A representative method for treating a patient in accordance with the disclosed technology includes receiving an input corresponding to an available voltage for an implanted medical device and identifying a signal delivery parameter value of an electrical signal based on a correlation between values of the signal delivery parameter and signal deliver amplitudes. The signal deliver parameter can include at least one of pulse width or duty cycle. The method can further include delivering an electrical therapy signal to the patient at the identified signal delivery parameter value using a voltage within a margin of the available voltage.

Systems and methods for selecting one or more sites at or within at least one heart chamber for cardiac stimulation are disclosed. The system can include a physiologic sensor circuit to sense physiologic signals at two or more candidate stimulation sites. The system can generate respective activation timing indicators corresponding to the two or more candidate stimulation sites, and detect MI indicators indicating the presence of, or spatial proximity of each of the two or more candidate stimulation sites to a MI tissue. The system can use the activation timing indicators and the MI indicators to select at least one target stimulation site or to determine an electrostimulation vector. The system can display the selected target stimulation site to a user, or deliver electrostimulation to the patient at the target stimulation site or according to the determined electrostimulation vector.