Abstract: Systems and methods for communicating between medical devices. In one example, an implantable medical device comprises a communication module configured to receive commands from other medical devices, wherein the commands include a relative address and a command payload; a memory unit that stores a relative address and a unique identifier of the implantable medical device; a processing module coupled to the communication module and the memory unit, the processing module configured to: determine whether the relative address of a received command matches the relative address stored in the memory unit of the implantable medical device; if the relative address of the received command matches the relative address stored in the memory unit of the implantable medical device, execute the received command; and if the relative address of the received command does not match the relative address stored in the memory unit of the implantable medical device, ignore the received command.

Abstract: Systems and methods for communicating between medical devices. In on example, a medical device comprises a communication module for communicating with an implantable leadless cardiac pacemaker through body tissue and a controller operatively coupled to the communications module. The controller may be configured to: identify intrinsic heartbeats; provide a blanking period after each occurrence of an intrinsic heartbeat; and communicate with the implantable leadless cardiac pacemaker via the communication module only during times between the blanking periods.

Abstract: Power saving communication techniques for communicating in a medical device system. One example medical device system may be for delivering electrical stimulation therapy to a heart of a patient, and may include a first implantable medical device implanted in a first chamber of the heart and configured to determine one or more parameters, a medical device physically spaced from and communicatively coupled to the first implantable medical device, the medical device configured to deliver electrical stimulation therapy to the heart of the patient, wherein the first implantable medical device is further configured to: compare a value of a first determined parameter to a first threshold; if the value of the first determined parameter passed the first threshold, communicate a first indication to the medical device; and if the value of the first determined parameter has not passed the first threshold, not communicating the first indication to the medical device.

Abstract: An implantable medical device comprises a non-volatile memory circuit including a configuration memory portion to store auto-configuration data for the IMD, a controller circuit, a reset circuit adapted to generate a reset signal and disable the controller circuit, and a startup circuit adapted to transfer the auto-configuration data from the configuration memory portion to one or more configuration registers in response to the reset signal, wherein values of the one or more configuration registers configure the IMD for a safety mode operation.

Abstract: Methods, systems, and apparatus for recharging medical devices implanted within the body are disclosed. An illustrative rechargeable system includes a charging device that includes an elongate shaft having a proximal section and a distal section. The distal section is configured to be delivered to a location within the body adjacent to the implanted medical device. The charging device includes a charging element configured to transmit charging energy to a receiver of the implanted medical device.

Abstract: An intra-body ultrasonic signal can be converted into a first electrical signal, a local oscillator signal can be generated in an implantable system. The first electrical signal and the local oscillator signal can be mixed in an implantable system, such as to generate a demodulated signal, processed, such as using a filter. The filtered, demodulated signal can be further processed, such as implantably determining a peak amplitude of the first portion of the demodulated signal received from the filter over a time interval, implantably generating a dynamic tracking threshold that starts at an amplitude proportional the first portion of the demodulated signal and exponentially decays over a time interval, and determining a noise floor in the absence of a received intra-body ultrasonic signal and implantably comparing the peak amplitude and the tracking threshold and generate the digital output based on the difference.

Abstract: Methods, systems, and apparatus for recharging medical devices implanted within the body are disclosed. An illustrative rechargeable system includes a charging device that includes an elongate shaft having a proximal section and a distal section. The distal section is configured to be delivered to a location within the body adjacent to the implanted medical device. The charging device includes a charging element configured to transmit charging energy to a receiver of the implanted medical device.

Abstract: An intra-body ultrasonic signal can be converted into a first electrical signal, a local oscillator signal can be generated in an implantable system. The first electrical signal and the local oscillator signal can be mixed in an implantable system, such as to generate a demodulated signal, processed, such as using a filter. The filtered, demodulated signal can be further processed, such as implantably determining a peak amplitude of the first portion of the demodulated signal received from the filter over a time interval, implantably generating a dynamic tracking threshold that starts at an amplitude proportional the first portion of the demodulated signal and exponentially decays over a time interval, and determining a noise floor in the absence of a received intra-body ultrasonic signal and implantably comparing the peak amplitude and the tracking threshold and generate the digital output based on the difference.

Abstract: An intra-body ultrasonic signal can be converted into a first electrical signal, a local oscillator signal can be generated in an implantable system. The first electrical signal and the local oscillator signal can be mixed in an implantable system, such as to generate a demodulated signal, processed, such as using a filter. The filtered, demodulated signal can be further processed, such as implantably determining a peak amplitude of the first portion of the demodulated signal received from the filter over a time interval, implantably generating a dynamic tracking threshold that starts at an amplitude proportional the first portion of the demodulated signal and exponentially decays over a time interval, and determining a noise floor in the absence of a received intra-body ultrasonic signal and implantably comparing the peak amplitude and the tracking threshold and generate the digital output based on the difference.

Abstract: An apparatus comprises an implantable medical device that includes a storage circuit. The storage circuit includes a first stage circuit configured to receive an input signal and to invert and store information about a data bit received in the input signal, a second stage circuit coupled to the output of the first stage circuit to invert and store information about a data bit received from the first stage circuit, and an error circuit coupled to the output of the first stage circuit and an output of the second stage circuit. The error circuit generates an error indication when the storage circuit outputs match while the first stage circuit and the second stage circuit are in an inactive state.

Abstract: A system and method for in situ trimming of oscillators in a pair of implantable medical devices is provided. Each frequency over a range of oscillator trim frequencies for an initiating implantable medical device is selected and a plurality of commands are sent via an acoustic transducer in situ over the frequency selected. Each frequency over a range of oscillator trim frequencies for a responding implantable medical device is selected and a response to each of the commands received is sent via an acoustic transducer in situ over the frequency selected. The responses received by the initiating implantable medical device are evaluated and a combination of the oscillator trim frequencies for both implantable medical devices that together exhibit a strongest acoustic wave is identified. Oscillators in both implantable medical devices are trimmed to the oscillator trim frequencies in the combination identified.

Abstract: A battery management circuit provides an implantable medical device with power management that allows safe and efficient use of a rechargeable battery. Various ways of monitoring the energy level of the rechargeable battery and controlling the battery recharging process for user convenience and safety are provided.

Abstract: An intra-body ultrasonic signal can be converted into a first electrical signal, a local oscillator signal can be generated in an implantable system. The first electrical signal and the local oscillator signal can be mixed in an implantable system, such as to generate a demodulated signal, processed, such as using a filter. The filtered, demodulated signal can be further processed, such as implantably determining a peak amplitude of the first portion of the demodulated signal received from the filter over a time interval, implantably generating a dynamic tracking threshold that starts at an amplitude proportional the first portion of the demodulated signal and exponentially decays over a time interval, and determining a noise floor in the absence of a received intra-body ultrasonic signal and implantably comparing the peak amplitude and the tracking threshold and generate the digital output based on the difference.

Abstract: A physiological sensor is located within the airway of the subject's body, such as for measuring barometric pressure and communicating this value to a blood pressure or other monitoring device, which can derive gauge pressure using the barometric pressure and a measured absolute pressure within the body. The physiological sensor may also detect one or more other physiological parameters such as air flow, sound, or a chemical property. It may be anchored within the airway with the ability to communicate wirelessly to one or more other medical devices, such as an implanted cardiac function management device. Methods of use are also described.

Abstract: An apparatus comprises an implantable medical device that includes a storage circuit. The storage circuit includes a first stage circuit configured to receive an input signal and to invert and store information about a data bit received in the input signal, a second stage circuit coupled to the output of the first stage circuit to invert and store information about a data bit received from the first stage circuit, and an error circuit coupled to the output of the first stage circuit and an output of the second stage circuit. The error circuit generates an error indication when the storage circuit outputs match while the first stage circuit and the second stage circuit are in an inactive state.

Abstract: A system and method for in situ trimming of oscillators in a pair of implantable medical devices is provided. Each frequency over a range of oscillator trim frequencies for an initiating implantable medical device is selected and a plurality of commands are sent via an acoustic transducer in situ over the frequency selected. Each frequency over a range of oscillator trim frequencies for a responding implantable medical device is selected and a response to each of the commands received is sent via an acoustic transducer in situ over the frequency selected. The responses received by the initiating implantable medical device are evaluated and a combination of the oscillator trim frequencies for both implantable medical devices that together exhibit a strongest acoustic wave is identified. Oscillators in both implantable medical devices are trimmed to the oscillator trim frequencies in the combination identified.

Abstract: A system and method for providing intrabody data security on an active implantable medical device is presented. Data is maintained through an active implantable medical device. The data is secured on the active implantable medical device among at least one other active implantable medical device wirelessly interfaced. At least one of access to and use of the data with the other active implantable medical device is limited. Unauthorized changes to the form of the data are prevented.

Abstract: A system includes multiple slave devices implanted in a human body, wherein each slave device includes a communication module operable to receive transmitted communications and is associated with a permanent device identifier. The system further includes a master device including a communications module operable to address a first communication to a selected slave device using the permanent device identifier associated with the selected slave device, wherein the first communication includes a local identifier assigned to the selected slave device, the assigned local identifier does not match any other local identifier assigned to any other slave device implanted in the human body, and subsequent communications are addressed to the selected slave device using the assigned local identifier.

Abstract: A physiological sensor is located within the airway of the subject's body, such as for measuring barometric pressure and communicating this value to a blood pressure or other monitoring device, which can derive gauge pressure using the barometric pressure and a measured absolute pressure within the body. The physiological sensor may also detect one or more other physiological parameters such as air flow, sound, or a chemical property. It may be anchored within the airway with the ability to communicate wirelessly to one or more other medical devices, such as an implanted cardiac function management device. Methods of use are also described.

Abstract: A battery management circuit provides an implantable medical device with power management that allows safe and efficient use of a rechargeable battery. Various ways of monitoring the energy level of the rechargeable battery and controlling the battery recharging process for user convenience and safety are provided.