An implantable medical device includes a housing with an outer surface that defines a first end and a second end opposite the first end, a battery assembly positioned within the housing between the first end and the second end, a first electrode positioned at or near the first end, a second electrode positioned at or near the second end, integrated circuitry positioned between the first end and the second end and electrically coupled to the first electrode, and an antenna communicatively coupled to the integrated circuitry and configured to wirelessly send and receive data to and from a receiver positioned externally to the implantable medical device.

Apparatus for use with a medical implant having a receiving coil. A flexible housing to be placed against skin of a subject includes a flexible transmitting coil and control circuitry for driving a current through the transmitting coil to induce a current in the receiving coil. A sensor coupled to the circuitry determines divergence of a resonance frequency of the transmitting coil when flexed from a nominal resonance frequency of the transmitting coil, occurring in the absence of any forces applied to the transmitting coil. One or more electrical components coupled to the circuitry tune the resonance frequency of the transmitting coil. A switch is coupled to each of the electrical components, the switches including transistors having capacitances that depend on the voltage applied to each switch. The circuitry applies a respective DC voltage to each switch. Other applications are also described.

Certain medical devices, such as auditory prostheses, have an implantable portion and an external portion. The implantable portion and external portion each include a transmission/receiver coil that communicates signals between the two portions. The implanted coil is implanted about the ear canal while the external coil is disposed about the pinna or in the ear canal itself. The proximity of the two coils allows for signal transmission between the implantable and external portions.

An inductance communication coil, including a conductor having at least one conductive turn, wherein a width of the conductor is wider at a first location relative to that at a second location. The conductor can be made out of metal. In some embodiments, the first location and the second location are on the same turn. In some embodiments, the conductor includes a plurality of turns, wherein the first location is at a first turn and the second location is at a second turn.

An on-body antenna is provided that overcomes mismatch loss problems associated with current on-body antennas and is capable of operating over a wide range of frequencies with low transmission loss. At least a first antenna element of the on-body antenna is configured to receive an oscillating electric current and to radiate an oscillating electromagnetic field over a predetermined range of frequencies. The first antenna element is made of non-electrically-conductive material having a first relative permittivity. At least a second material having a second relative permittivity can be disposed on or in the first antenna element. Disposing the second material provides the first antenna element with an effective permittivity that can be closely matched to a frequency-dependent permittivity of biological tissue of a subject. The first non-electrically-conductive material and the second material can be preselected to have relative permittivities that allow anisotropy to be achieved.

A subcutaneously implantable device includes a housing, a clip attached to the housing that is configured to anchor the device to a muscle, a bone, and/or a first tissue, and circuitry in the housing that is configured to provide monitoring, therapeutic, and/or diagnostic capabilities with respect to an organ, a nerve, the first tissue, and/or a second tissue. The circuitry includes a first power source, and a transceiver. A first antenna on the device is in electrical communication with the first power source. The first antenna is configured to be subcutaneously positioned in a patient. A second antenna on the device is in electrical communication with the transceiver. The second antenna is configured to be subcutaneously positioned in the patient.

Systems and apparatuses are used to transmit data between external and internal portions of auditory prostheses or other medical devices. The external portion of the auditory prosthesis includes a magnet and an implanted coil that provides stimulation to the device recipient. A shaped shield material can be placed between the external coil and the sound processing hardware to improve efficiency and effectiveness between the external coil and implanted coil. Adverse effects on tuning frequencies can be reduced by disposing the shield material away from the magnet.

Described herein are devices, systems, and methods for wireless power transfer utilizing a midfield source and implant. In one variation, a midfield source may be realized by a patterned metal plate composed of one of more subwavelength structures. These midfield sources may manipulate evanescent fields outside a material (e.g., tissue) to excite and control propagating fields inside the material (e.g., tissue) and thereby generate spatially confined and adaptive energy transport in the material (e.g., tissue). The energy may be received by an implanted device, which may be configured for one or more functions such as stimulation, sensing, or drug delivery.

Methods of providing electrical neural modulation to a patient's brain are disclosed herein. The methods involve differentially modulating two or more target regions of the brain. For example, a first target region may be provided with an electrical neural modulation signal that activates that target region while a second target region is provided with an electrical neural modulation signal that suppresses or deactivates that target region. As the implantable pulse generators (IPGs) described herein include independent current sources, such differential modulation can be provided with a single IPG.

A device for securing an external transmitter of a cochlear implant to the head of the wearer. A pouch containing the external transmitter is secured using a plurality of straps coupled to a decorative shell worn on a person's head. The pouch and the decorative shell are designed to allow sound to pass unhindered from the environment to the inner ear. The plurality of straps is adjustable to allow precise placement of the external transmitter over the internal receiver. The external transmitter is also secured using a pouch coupled to a decorative shell. The external transmitter is further secured using a sealer coupled to the transmitter and further coupled to the head using an adhesive barrier. The sealer is made of a semi-transparent material. The device ensures that an external transmitter remains in place.