Heart rhythm is stabilized within the heart's free running cycle by detecting arrhythmias in a mammalian subject, and then electronically stimulating the subject's vagus and cardiac sympathetic nerves. More specifically, vagus efferents are stimulated to directly cause heart rate to slow down, while cardiac sympathetic nerve efferents are stimulated to cause the heart rate to quicken. Simultaneously, afferents from vagus and/or cardiac sympathetic nerves induce the brain to employ the brain's natural mechanisms of heart rhythm control. Such nerve stimulation works in harmony with the body's natural mechanisms of heart rhythm control.

A power management system and technique to manage and allocate the energy provided to various components of an implanted device during periods of low energy. The power management system includes an implantable power source delivering energy to various components within the implantable medical device, a measurement device to measure the energy of the power source, and a processor responsive to the measurement device. The processor monitors the energy level of the power source. During periods of low energy, the processor limits the energy to certain device-critical components of the implantable medical device. This minimizes the risk of damage to the power source resulting from high energy drain during periods of low energy. Further, this preserves operation of device-critical components of the implanted device during periods of low energy.

In one embodiment, an implantable medical device comprises: a rechargeable battery for powering the implantable medical device; an antenna for receiving RF power; and circuitry for charging the rechargeable battery using power received via the antenna, wherein the circuitry for charging comprises control circuitry that causes the circuitry for charging to recharge the rechargeable battery using multiple current levels applied in succession, and wherein the circuitry for charging switches from at least one of the current levels to another current level when a charging voltage of the rechargeable battery reaches a threshold value that is varied by the control circuitry over a lifespan of the rechargeable battery.

An implantable medical device having an implantable power source such as a rechargeable lithium ion battery. The implantable medical device includes a recharge module that regulates the recharging process of the implantable power source using closed-loop feedback control. The recharge module includes a recharge regulator, a recharge measurement device monitoring at least one recharge parameter, and a recharge regulation control unit for regulating the recharge energy delivered to the power source in response to the recharge measurement device. The recharge module adjusts the energy provided to the power source to ensure that the power source is being recharged under safe levels.

System and method for end of battery life operation of an implantable bilateral brain stimulator. The present system and method automatically measures one or more levels of electrical parameters in a battery system of the implantable stimulator. The measurement can be compared to threshold values. The implantable bilateral brain stimulator can then make automatic adjustments to the therapy when the levels of the electrical parameters in the battery system reach the threshold values. Adjustments to the therapy are made such that the patient is provided with an adjusted, but sufficiently safe, amount of therapy so as to extend the life of the battery and also to allow some physical symptoms alleviated by the system to return, thereby signaling the patient that medical attention needs to be sought.