Abstract: An apparatus and method for enabling an implanted fractal antenna for radio frequency communications between an implantable medical device and an external device. The fractal antenna may be disposed within or outside of a header assembly of the device housing. Various examples include a three dimensional patterned cylinder usable as a tissue anchor or stent. In another embodiment the antenna may be cast, molded, stamped, punched, milled, laser cut, etched or other methods to form a fractal pattern in conductive media. In another embodiment the antenna may be formed of a printed circuit board (PCB) either with or without an included ground reference plane. In another embodiment the antenna may be formed in a fractal pattern and then wrapped around a part of the implantable device.

Abstract: An apparatus comprises a transceiver configured to communicate wirelessly with an IMD and a processor communicatively coupled to the transceiver. The processor is configured to detect an error in a data unit received from the IMD, transmit a series of synchronization signals during an uninterrupted communication sequence, and receive, for each synchronization signal, a new data unit and the number of requested duplicate data units from the IMD. Each synchronization signal includes an echo code, wherein the echo code corresponds to a request for a number of duplicate data units to be sent in response to detecting the error in the data unit received during said uninterrupted communication sequence. The number of duplicate data units corresponds to a value of the echo code, and a duplicate data unit corresponds to a data unit previously transmitted by the IMD during said uninterrupted communication sequence.

Abstract: An apparatus and method for enabling far-field radio frequency communications with an implantable medical device in which an antenna structure is disposed within a header assembly of the device. The antenna structure, in various embodiments, includes a monopole antenna, a dipole antenna, an inverted F antenna, a patch antenna and a slot antenna.

Abstract: A far-field radio frequency (RF) telemetry system for communicating with an implantable medical device includes a diversity antenna system. Multi-frame messages each including multiple outgoing data frames are transmitted to the implantable medical device. In response, the implantable medical device transmits response data frames each following one or more of the outgoing data frames, according to a predetermined communication protocol. An antenna control circuit selects an antenna of the diversity antenna system for transmitting the outgoing data frames and/or receiving the response data frames based on the quality of signal reception associated with the response data frames.

Abstract: An apparatus and method for enabling an implanted fractal antenna for radio frequency communications between an implantable medical device and an external device. The fractal antenna may be disposed within or outside of a header assembly of the device housing. Various examples include a three dimensional patterned cylinder usable as a tissue anchor or stent. In another embodiment the antenna may be cast, molded, stamped, punched, milled, laser cut, etched or other methods to form a fractal pattern in conductive media. In another embodiment the antenna may be formed of a printed circuit board (PCB) either with or without an included ground reference plane. In another embodiment the antenna may be formed in a fractal pattern and then wrapped around a part of the implantable device.

Abstract: A system for communicating with an implantable medical device via RF telemetry is disclosed which mitigates the effects of nulls caused by, e.g., multi-path distortion. In one embodiment, signals transmitted by the implantable device to an external device are simultaneously received with a pair of separate spaced apart first and second antennas. The antennas may provide spatial and/or polar diversity. The presence of nulls in the implantable device's transmission pattern can be determined by detecting an error rate in the signals received from the implantable device with each antenna.

Abstract: A diversity antenna system including a plurality of antennas can include an antenna interface circuit configured to connect an antenna of the plurality of antennas to a transceiver using an antenna selection signal. The antenna control circuit can be configured to produce the antenna selection signal using at least one of a random sequence generator configured to generate a random antenna selection signal or a predetermined sequence generator configured to generate a predetermined antenna selection signal according to a predetermined sequence.

Abstract: An implantable medical device can include an implantable antenna for communication with external devices or other internal devices. Changes in the patient's body position, weight, composition or other factors may change the efficiency of the implantable antenna and hinder communication. The disclosed circuit can calculate a value for a matching network for an implantable telemetry circuit to decrease an impedance difference between the implantable telemetry circuit and the implantable antenna or increase or maximize a communication power transfer value associated with the implantable medical device.

Abstract: A far-field radio frequency (RF) telemetry system for communicating with an implantable medical device includes a diversity antenna system. Multi-frame messages each including multiple outgoing data frames are transmitted to the implantable medical device. In response, the implantable medical device transmits response data frames each following one or more of the outgoing data frames, according to a predetermined communication protocol. An antenna control circuit selects an antenna of the diversity antenna system for transmitting the outgoing data frames and/or receiving the response data frames based the quality of signal reception associated with the response data frames.

Abstract: An apparatus and method for enabling far-field radio frequency communications with an implantable medical device in which an antenna structure is disposed within a header assembly of the device. The antenna structure, in various embodiments, includes a monopole antenna, a dipole antenna, an inverted F antenna, a patch antenna and a slot antenna.

Abstract: A far-field radio frequency (RF) telemetry system for communicating with an implantable medical device includes a diversity antenna system. Multi-frame messages each including multiple outgoing data frames are transmitted to the implantable medical device. In response, the implantable medical device transmits response data frames each following one or more of the outgoing data frames, according to a predetermined communication protocol. An antenna control circuit selects an antenna of the diversity antenna system for transmitting the outgoing data frames and/or receiving the response data frames based the quality of signal reception associated with the response data frames.

Abstract: An apparatus and method for enabling far-field radio frequency communications with an implantable medical device in which an antenna structure is disposed within a header assembly of the device. The antenna structure, in various embodiments, includes a monopole antenna, a dipole antenna, an inverted F antenna, a patch antenna and a slot antenna.

Abstract: A diversity antenna system including a plurality of antennas can include an antenna interface circuit configured to connect an antenna of the plurality of antennas to a transceiver using an antenna selection signal. The antenna control circuit can be configured to produce the antenna selection signal using at least one of a random sequence generator configured to generate a random antenna selection signal or a predetermined sequence generator configured to generate a predetermined antenna selection signal according to a predetermined sequence.

Abstract: A far-field radio frequency telemetry (RF) system for communicating with an implantable medical device includes a diversity antenna system. An antenna control circuit selects one or more antennas of the diversity antenna system for reducing potential data transmission errors associated with nulls encountered by the telemetry system due to environmental reflections of RF electromagnetic waves. In one embodiment, a different active antenna is selected when a transmission failure deemed to be associated with a null is detected. In another embodiment, a new antenna is selected on a regular basis to reduce the probability of encountering a null. In another embodiment, the telemetry system includes multiple processing paths each associated with one antenna of the diversity antenna system, and a different processing path is selected when the transmission failure deemed to be associated with a null is detected.

Abstract: A telemetry system provides a selectable encoding protocol, including, for example, a plurality of redundancy levels, where the encoding protocol is selected based on a measure of transmission efficiency. For example, later messages are transmitted using an increased redundancy if a prior message exhibits a low signal to noise ratio. A communication session is initiated using a first level of redundancy and the level is adjusted based on a channel characteristic or a measured parameter.

Abstract: This document discloses, among other things, a telemetry system for requesting and receiving redundant data. A synchronization frame transmitted by an external device includes an echo code. The implantable device responds to the synchronization frame by sending real time data and echo data selected as a function of the echo code.

Abstract: This document discloses, among other things, a telemetry system for requesting and receiving redundant data. A synchronization frame transmitted by an external device includes an echo code. The implantable device responds to the synchronization frame by sending real time data and echo data selected as a function of the echo code.

Abstract: An implantable medical device can include an implantable antenna for communication with external devices or other internal devices. Changes in the patient's body position, weight, composition or other factors may change the efficiency of the implantable antenna and hinder communication. The disclosed circuit can calculate a value for a matching network for an implantable telemetry circuit to decrease an impedance difference between the implantable telemetry circuit and the implantable antenna or increase or maximize a communication power transfer value associated with the implantable medical device.

Abstract: A far-field radio frequency (RF) telemetry system for communicating with an implantable medical device includes a diversity antenna system. Multi-frame messages each including multiple outgoing data frames are transmitted to the implantable medical device. In response, the implantable medical device transmits response data frames each following one or more of the outgoing data frames, according to a predetermined communication protocol. An antenna control circuit selects an antenna of the diversity antenna system for transmitting the outgoing data frames and/or receiving the response data frames based the quality of signal reception associated with the response data frames.

Abstract: An implantable medical device may have an antenna for communication with external devices or other internal devices. Changes in the patient's body position, weight, composition or other factors may change the antenna efficiency and hinder communication. The disclosed circuit may automatically adjust a matching network for an implanted transceiver to dynamically maximize transmission and reception by controlling the selected value of a plurality of capacitors, inductors and resistors.