Abstract: This disclosure describes to techniques to compensate for distortions introduced into received signals by one or more receiver components that have undesirable electrical responses, such as nonlinear phase response, sloped (or non-flat) amplitude response or both. An external device or other device with more power resources than an IMD filters signals to be transmitted to the IMD to pre-compensate for distortions introduced by the undesired electrical responses of the one or more receiver components of the IMD. In this manner, at least a portion of the burden of digital processing to compensate for undesired electrical responses of the receiver components is shifted from the IMD to the external device, which is better equipped to perform such heavy computationally complex functions.

Abstract: The invention is directed to structure and methods for coordinating the operation of an implantable medical device (IMD) with magnetic resonance imaging (MRI) techniques. For example the IMD can be made to activate a blanking period during the time when the electromagnetic radiation bursts occur. Blanking an IMD at times when MRI electromagnetic radiation bursts occur can prevent an undesirable action or incorrect sensing by the IMD while under the influence of the electromagnetic radiation bursts.

Abstract: An implantable medical device (IMD) can include an implantable pulse generator (IPG), such as a cardiac pacemaker or an implantable cardioverter-defibrillator (ICD). Various portions of the IMD, such as a device body, a lead body, or a lead tip, can be provided to reduce or dissipate a current and heat induced by various external environmental factors. According to various embodiments, features can be incorporated into the lead body, the lead tip, or the IMD body to reduce the creation of an induced current, or dissipate the induced current and heat created due to an induced current in the lead.

Abstract: An electromagnetic shield has a first patterned or apertured layer having non-conductive materials and conductive material and a second patterned or apertured layer having non-conductive materials and conductive material. The conductive material may be a metal, a carbon composite, or a polymer composite. The non-conductive materials in the first patterned or apertured layer may be randomly located or located in a predetermined segmented pattern such that the non-conductive materials in the first patterned or apertured layer are located in a predetermined segmented pattern with respect to locations of the non-conductive materials in the second patterned or apertured layer.

Abstract: Techniques are described for detecting a condition of a patient using a probability-correlation based model that integrates a plurality of parameters associated with the condition. A medical device that operates in accordance with the techniques obtains a plurality of parameters associated with the condition of the patient. The medical device obtains probabilities that the condition of the patient exists based on each single parameter separately and correlations between each of the parameters and the other ones of the parameters. After obtaining the probabilities and correlations associated with each of the parameters, the medical device determines whether the condition of the patient exists based on the determined probabilities and correlations. Such techniques may be particularly effective for use in distinguishing whether a rhythm of a patient is treatable, e.g., VT or VF, or non-treatable, e.g., SVT.

Abstract: A system and method are provided for the detection of acute myocardial infarction (AMI) using a staged approach for accurate and rapid detection. Physiological signals in a patient's body are sensed and corresponding physiological parameters are derived in a staged approach in order to determine the probability that AMI is occurring in a patient in a first detection stage. If the computed probability from physiological signals indicates the possibility of AMI, then the patient is prompted, such as through a patient-wearable device, to answer specific AMI-related questions to assist in diagnosis of AMI in a second stage. AMI is detected when the computed probability in the second stage exceeds a predefined detection threshold. A patient or physician alert may then be generated, which may further include the transfer of data via a communication link or network, in response to an AMI detection signal.

Abstract: Unscheduled wireless communication with a medical device is achieved by operating a receiver of the medical device in a series of modes. Each mode provides an increasingly selective evaluation of received RF energy. The receiver, when operating in a first mode, is capable of detecting the presence of RF energy transmitted from a communicating device. The receiver, when operating in a second mode, consumes more energy than the first mode and analyzes the RF energy to determine whether it contains the appropriate type of modulation. When operating in a third mode, the receiver consumes more energy than the second mode, and operates the full receiver to begin communication with the communicating device. The receiver opens a communication session after the RF energy has passed the evaluation by the series of modes to receive an unscheduled communication.

Abstract: A communications protocol is used to provide data privacy, message integrity, message freshness, and user authentication to telemetric traffic, such as to and from implantable medical devices in a body area network. In certain embodiments, encryption, message integrity, and message freshness are provided through use of token-like nonces and ephemeral session-keys derived from device identification numbers and pseudorandom numbers.

Abstract: The disclosure is directed to techniques in which magnetic resonance imaging (MRI) is coordinated with the operation of an implantable medical device (IMD). By using an IMD to sense conditions, MRI can be improved because the sensed conditions can accurately define timing for application of electromagnetic radiation bursts. Moreover, by applying stimulation pulses specifically to coordinate the electromagnetic radiation bursts, the MRI may also be improved.

Abstract: An IMD is selectively configurable to support a plurality of programming options for enabling and disabling an exposure operating mode of the device. In one example, the IMD may support at least two of a manual exposure mode programming option in which the exposure operating mode is manually enabled and manually disabled, an automatic exposure mode programming option in which the exposure operating mode is automatically enabled and automatically disabled, or a semi-automatic exposure mode programming option in which the exposure operating mode is either automatically enabled and manually disabled or manually enabled and automatically disabled. In this manner, the IMD may support more than one way for enabling and disabling the exposure operating mode to provide flexibility in the clinical workflows associated with programming the IMD into an exposure operating mode for a medical procedure, such as an MRI scan.

Abstract: Techniques for determining whether a lead related condition exists based on analysis of a cardiac electrical signal associated with a non-sustained tachyarrhythmia (NST) are described. In some examples, the techniques include determining the duration of intervals between consecutive cardiac events, e.g., R-R intervals, during an NST. The techniques may further include determining one or more metrics based on the durations of the intervals during the NST. Examples of metrics include an average, a minimum, a maximum, a range, a median, a mode, or a mean. A lead related condition is identified based on the values of the one or more metrics, e.g., by comparison to respective thresholds. In some examples, an alert is provided or a therapy modification is suggested if a lead related condition is identified.

Abstract: An implantable medical device (IMD) communication system and associated method for controlling the telemetry link status between an IMD and associated programmer during a telemetry session are provided. The system includes control circuitry for detecting conditions during predetermined time intervals for determining if a telemetry session is active or inactive. If a telemetry session is determined to be inactive for a specified interval of time, the telemetry link may be terminated or converted to a low-output, stand-by mode. Patient or device identity verification may be required prior to allowing programmer-IMD communication. A patient alert signal may be generated in response to programmer-IMD communication occurring after a predetermined time of telemetry session inactivity.

Abstract: A medical device includes a sensor for sensing for an MRI gradient magnetic field and a microprocessor configured to operate in a signal processing mode in which electrical signals induced by the gradient magnetic field are not counted as cardiac events.

Abstract: A telemetry antenna for an implantable medical device includes one or more segments having a non-linear configuration. In some embodiments, the non-linear configuration provides an antenna having a greater antenna length than the linear lengthwise dimension of the antenna structure. In some embodiments, the non-linear configuration includes a plurality of trapezoidal unit structures.

Abstract: An implantable medical device (IMD) can include an implantable pulse generator (IPG), such as a cardiac pacemaker or an implantable cardioverter-defibrillator (ICD). At least one lead is coupled to the IMD at a proximal end to the anatomic tissue of a patient at a distal end. According to various embodiments, a one-quarter wavelength open circuit terminated transmission line forms a stub filter to attenuate an interfering signal, such as those created by an MRI scanner during an MRI procedure. By cancelling the interfering signal, both the IMD and patient are protected from any adverse effects caused by the interfering signal.

Abstract: An implantable medical assist device includes a medical device. The medical device has a housing and electronics contained therein. A lead provides an electrical path to or from the electronics within the medical device. A resonance tuning module is located in the housing and is connected to the lead. The resonance tuning module includes a control circuit for determining a resonant frequency of the implantable medical assist device and an adjustable impedance circuit to change the combined resonant frequency of the medical device and lead.

Abstract: A communications protocol is used to provide data privacy, message integrity, message freshness, and user authentication to telemetric traffic, such as to and from implantable medical devices in a body area network. In certain embodiments, encryption, message integrity, and message freshness are provided through use of token-like nonces and ephemeral session-keys derived from device identification numbers and pseudorandom numbers.

Abstract: Medical data is communicated from a transmitter of an external unit to a receiver of an implantable medical device. The transmitter generates a preamble signal having encoded configuration data that informs the receiver of configuration settings to be used in receiving the medical data. The receiver detects the preamble and validates a modulation pattern of the preamble. Configuration data is decoded from the preamble signal and the receiver configuration is adjusted to receive the medical data.

Abstract: An implantable medical system includes a first die substrate with a first outer surface. The system also includes a second die substrate with a second outer surface. Furthermore, the system includes a medical device with a first portion that is mounted to the first die substrate and a second portion that is mounted to the second die substrate. The first and second die substrates are fixed to each other and substantially hermetically sealed to each other. Also, the medical device is substantially encapsulated between the first and second die substrates. The first portion is electrically connected to the second portion. Moreover, the first and second outer surfaces of the first and second die substrates are directly exposed to a biological material.

Abstract: A plurality of phases of sniff operations are performed for detecting wake-up signals being received by an implantable medical device (IMD), including a phase that performs a staged detection of whether the integrated frequency deviation of a received signal is outside of an expected frequency deviation range, where sniff operations are aborted if the integrated frequency deviation of the received signal falls outside of corresponding high and low thresholds in any stage, wherein the difference between the high and low thresholds tightens with each subsequent stage and an average frequency deviation over all completed stages are used in the calculations. One phase of sniff operations includes a dual frequency modulation (FM) detector including a first FM detector that introduces a small delay in a received signal providing an average frequency estimate and a second FM detector having a larger delay that is adjusted based on the estimated average frequency.