Abstract: A base station for passively recharging a battery in an implant without patient involvement is disclosed. The base station can be hand held or may comprise equipment configured to be placed at a fixed location, such as under a bed, on or next to a wall, etc. The base station can generate electric and magnetic fields (E-field and B-field) that couple with an antenna and a receiving coil within the implant to generate a charging current for charging the implant's battery. No handling or manipulation on part of the patient is necessary; the implant battery is passively charged whenever the patient is within range of either the magnetic or electric charging fields generated by base station. Charging using the B-field occurs when the IPG is at a relatively short distance from the base station, while charging using the E-field occurs at longer distances.

Abstract: An implantable medical device and external base station system are disclosed. The external base station can provide a passive electric field to power the implant, or to charge its battery. The base station may also power or charge using magnetic fields under certain circumstances. The Implantable medical device may comprise an implantable neurostimulator having a number of electrode leads extending from its body. One or more of the electrode leads can comprise the antenna for receiving the electric field from the base station, and resonance in that antenna can be rectified to provide the power for recharging the battery. Although the E-field provided by the base station does not provide as much power for recharging as does other traditional charging techniques (such as those using magnetic fields), it can occur passively and over longer distances to allow the patent's implant to be recharged when in relative proximity to the base station.

Abstract: Disclosed is an improved medical implantable device having a conductive case into which a slot antenna is formed. The slot antenna preferably has a slot length which is one-half of the wavelength of the data being sent to or received from an external controller, although slot lengths smaller than these ideals values can also be used albeit with reduced efficiency. Slot lengths accommodatable by a given case can enable communications at frequencies suitable for medical telemetry. The slot is preferably filled with a hermetic dielectric material, and can be formed into different geometries, including non-linear geometries. When the slot antenna is provided in the implant's case, separate data antennas or coils are not needed, which reduces the implant's size. Additionally, the slot antenna reduces eddy current heating in the case, and promotes efficient data transfer in the near field that is not as susceptible to attenuation in the human body.

Abstract: A driving circuit useful in a magnetic inductive coupling wireless communication system is disclosed. The circuit includes an inductor (coil; L) and capacitor (C) in series selectively coupled to a power source such as a rechargeable battery. The LC circuit is made to resonate in accordance with a Frequency Shift Keying (FSK) or other protocol. Such resonance produces a voltage across the inductor. This voltage is used to create a first voltage either by tapping into the coil, or by providing a transformer. The first voltage is coupled to the rechargeable battery by a diode. When the circuit resonates, and when the first voltage exceeds the voltage of the power source, the diode turns on, thus shunting excess current back to recharge the rechargeable battery. By use of this circuit, energy is conserved. Additionally, oscillations can be quickly dampened so as to allow the circuit to transmit at high data rates.