Abstract: Integrity of a wirelessly telemetered message communicated between an implantable medical device and an external programmer is authenticated by encoding the message. The message is encrypted based on a random number or time stamp and a secret key. The message is authenticated by encryption and decryption or by executing a hash function.

Abstract: A system and method for waking up an implantable medical device (“IMD”) from a sleep state in which power consumption by the IMD is essentially zero. The IMD may be adapted to perform one or more designated measurement and/or therapeutic functions. In one embodiment, the IMD includes a wake-up sensor that is adapted to sense the presence or absence of a wake-up field generated by another IMD or an external device. The wake-up field may, in some embodiments, be an electromagnetic field, a magnetic field, or a physiologically sub-threshold excitation current (i.e., E-field). Upon sensing by the wake-up sensor of the wake-up field, other components of the IMD, which may include a controller, a sensing and/or therapy module, and/or a communications module, are awakened to perform one or more designated functions.

Abstract: An apparatus and method is presented for an implanted sound sensor wirelessly communicating with an implantable medical device, or with an external monitoring device. The second sensor may be located inside a blood vessel anchored by an expandable stent like device, and may be drug coated. The sound sensor may be a solid-state microphone having a unidirectional characteristic and may be aimed at a selected portion of the heart, lung, or other location. There may be a network of sound sensors forming a local area network with the implantable medical device. The information from the sound sensor may be analyzed, filtered, transformed, compared to a standard and stored in the implantable device, or it may be passed on to an external location. The results of the analysis may be use to initiate a closed-loop treatment by the implantable medical device, such as cardiac pacing or defibrillation.

Abstract: A telemetry system for radio-frequency communications between an implantable medical device and an external device providing improved noise immunity is disclosed. Multiple communications channels are used to enable establishment and re-establishment of communications between a particular pair of devices in a multiple device environment.

Abstract: A method and system for enabling secure communications between an implantable medical device (IMD) and an external device (ED) over a telemetry channel. A telemetry interlock may be implemented which limits any communications between the ED and the IMD over the telemetry channel, where the telemetry interlock is released when the ED transmits an enable command to the IMD via a short-range communications channel requiring physical proximity to the IMD. As either an alternative or addition to the telemetry interlock, a data communications session between the IMD and ED over the telemetry channel may be allowed to occur only after the IMD and ED have been cryptographically authenticated to one other.

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 implantable medical device (IMD) is adapted for detecting acoustic chest sounds. The IMD includes a pulse generator having a compartment, the compartment defining an isolated cavity bounded by a back wall. A diaphragm is disposed over and encloses the cavity. An acoustic sensor adapted to sense chest sounds and generate a signal is disposed between the diaphragm and the back wall. The IMD also includes a control circuit disposed within the pulse generator. The circuit is operatively coupled to the acoustic sensor and is adapted to receive the signal.

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 for radio-frequency communications between an implantable medical device and an external device providing improved noise immunity is disclosed. Multiple communications channels are used to enable establishment and re-establishment of communications between a particular pair of devices in a multiple device environment.

Abstract: An implantable medical device system includes an implanted device communicating with an external device via telemetry. The implanted device and the external device each have a telemetry module connected to an antenna system to support a radio-frequency (RF) telemetry link. The antenna system of the external device has a manually or automatically controllable directionality. The controllable directionality is achieved, for example, by using two or more directional antennas, one non-directional antenna and one or more directional antennas, or an electronically steerable phased-array directional antenna.

Abstract: Methods and systems provide for anchoring implantable medical device inside a bodily vessel. An anchoring structure can include a stent-like structure to which the IMD is attached. The stent-like structure is positioned at a desired location in the bodily vessel. The stent-like structure can be repositioned based on a measurement from the IMD. The IMD can include outwardly extending fins over which tissue can fibrose to affix the IMD to a wall of the bodily vessel. The stent-like structure can be made of a bio-absorbable material. The IMD can be attached to a stent-like structure by leads, by being lodged in a recessed diaphragm, by being embedded in mesh of the stent-like structure, or other methods. The stent-like structure can be balloon deployable to allow for controlled positioning and anchoring. The anchoring structure can include a vena cava filter.

Abstract: A method carried out by an implantable medical device (IMD) for coordinating performance of one or more designated functions includes waiting in a low-power state for a predetermined event, detecting the predetermined event, and, responsive to detecting the predetermined event, searching for a wake-up command from a coordinating device implanted in the human body. The method further includes, receiving the wake-up command, and responsive to receiving the wake-up command, performing the one or more designated functions, and returning to the low-power state. A system includes a network of one or more implantable medical devices (IMDs) implanted in a human body. The system includes a satellite IMD operable to change between a plurality of power states, search for a wake-up command, and transmit an identification signal. The system may include a primary unit operable to receive the signal and coordinate a wake-up time based on the signal.

Abstract: A telemetry system enabling radio frequency (RF) communications between an implantable medical device and an external device, or programmer, in which the RF circuitry is normally maintained in a powered down state in order to conserve power. At synchronized wakeup intervals, one of the devices designated as a master device powers up its RF transmitter to request a communications session, and the other device designated as a slave device powers up its RF transmitter to listen for the request. Telemetry is conducted using a far field or near field communication link.

Abstract: One embodiment of the present invention relates to a system for deriving physiologic measurement values that are relative to ambient conditions. In one embodiment, the system comprises an implantable medical device (“IMD”) and an external monitor. The IMD is adapted to determine an absolute physiologic parameter value within a patient's body, and communicate the absolute physiologic parameter value outside the patient's body, for example, to the external monitor. Further, the external monitor is adapted to receive the absolute physiologic parameter from the IMD and obtain an ambient condition value outside the body that can affect the absolute physiologic parameter value. The external monitor then calculates a relative physiologic parameter value from the ambient condition value and the absolute physiologic parameter value.

Abstract: One embodiment of the present invention relates to a system for deriving physiologic measurement values that are relative to ambient conditions. In one embodiment, the system comprises an implantable medical device (“IMD”), an external computing device, and a backend computing system. The IMD determines an absolute physiologic parameter value within a patient's body, and communicates the absolute physiologic parameter value outside the patient's body, for example, to the external computing device. Further, the external computing device receives the absolute physiologic parameter from the IMD and communicates it to the backend computing system. The backend computing system receives the absolute physiologic parameter value and obtains an ambient condition value outside the body that can affect the absolute physiologic parameter value.

Abstract: One embodiment of the present invention relates to a system for deriving physiologic measurement values that are relative to ambient conditions. In one embodiment, the system comprises an implantable medical device (“IMD”) and an external computing device. The IMD is operable to determine an absolute physiologic parameter value within a patient's body, and communicate the absolute physiologic parameter value outside the patient's body, for example, to the external computing device. Further, the external computing device is operable to receive the absolute physiologic parameter from the IMD and obtain an ambient condition value outside the body that can affect the absolute physiologic parameter value. The external computing device then calculates a relative physiologic parameter value from the ambient condition value and the absolute physiologic parameter value.

Abstract: One embodiment of the present invention relates to a system for deriving physiologic measurement values that are relative to ambient conditions. In one embodiment, the system comprises an implantable medical device (“IMD”), which includes a main body; and a remote sensor system operable to measure an absolute physiologic parameter value within a patient's body. The system further comprises an external device, which can be operable to obtain an ambient condition value outside the patient's body that can affect the absolute physiologic parameter value, and communicate the ambient condition value to the remote sensor system. In accordance with one embodiment, the remote sensor system then can be further operable to receive the ambient condition value and calculate a relative physiologic parameter value from the ambient condition value and the absolute physiologic parameter value.

Abstract: An implantable cardiac device is configured and programmed to collect blood pressure waveforms from one or more implantable pressure sensors. Techniques are described for extracting features and reducing noise in the pressure waveforms by averaging waveforms which are aligned with a detected cardiac cycle. Noise can also be reduced by gating and calibration functions performed in accordance with other sensor data.

Abstract: A system and method for providing digital data communications over a wireless intra-body network is presented. A physical protocol layer is logically defined with an identifier uniquely assigned to a plurality of implantable devices in an intra-body network. Functions are specified within the physical protocol layer to transact data exchange over a wireless interface. A slave implantable device is activated in response to an activation signal transmitted through the wireless interface by a master implantable device. A wireless communications link is established between the slave implantable device and the master implantable device upon matching of the identifier assigned to the slave implantable device. Data is communicated intra-bodily over the communications link.

Abstract: An implantable medical device includes a radio-frequency (RF) telemetry circuit connected to an energy source through a power connection module to obtain power when a user initiates an RF telemetry session. After the session is completed, the power connection module shuts off the at least one portion of the RF telemetry circuit. Power-on examples include a wireless telemetry activation signal received by a low power radio receiver in the implantable device, a physical motion detected by an activity sensor therein, an activation of an inductive telemetry circuit therein, a magnetic field detected by a magnetic field detector therein, and/or a telemetry activation signal detected by a sensing circuit included therein. Power-off examples include a wireless termination signal received by the implantable device, a delay timeout after the session, and/or a signal received by an inductive telemetry circuit in the implantable device.