Abstract: An implanted system includes at least two optical sensors implanted proximate to an artery of a patient such that one optical sensor is upstream of another optical sensor. Arterial pulses of the patient may be detected based on electrical signals from at least one of the optical sensors. In addition, electrical signals from the optical sensors may be used to minimize the effects of motion artifacts on the detection of arterial pulses. For example, a detected pulse may be determined to be a spurious pulse if the optical sensors indicate the occurrence of the pulse within a predetermined range of time. As another example, a first optical sensor signal may be shifted in time relative to a second optical sensor signal, and the signals may be correlated. An arterial pulse may be detected at a time at which a peak or trough amplitude value of the correlated signal is observed.

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: An implantable medical device has a first module for performing telemetry communications with another device and a second module for delivering a high voltage therapy to a patient. The first module is configured to detect a communication error, and the second module is configured to determine a need for the therapy and to charge a capacitor in response to the need for the therapy. The second module is configured to suspend the capacitor charging in response to receiving a notification from the first module corresponding to detecting a communication error.

Abstract: A wireless data communication card configured in accordance with an example embodiment of the invention includes a low profile antenna arrangement that does not protrude from the housing of the computing device when the wireless data communication card is inserted into the housing. The low profile design is achieved without compromising the radio frequency (“RF”) characteristics and performance of the wireless data communication card by tuning the antenna arrangement to account for conductive ground structure located within the housing of the computing device. In accordance with one practical embodiment of the invention, the wireless data communication card is compliant with IEEE Standard 802.11(b) and compliant with PCMCIA specifications.

Abstract: Techniques for performing a lead integrity test during a suspected tachyarrhythmia are described. An implantable medical device (IMD) may perform the test prior to delivering a therapeutic shock to treat the suspected tachyarrhythmia and, in some cases, may withhold the shock based on the test. In some examples, the IMD measures an impedance of a lead a plurality of times during the suspected tachyarrhythmia. In some examples, the IMD measures the impedance a plurality of times between two sensed events of the suspected tachyarrhythmia. The IMD or another device may determine a variability of, or otherwise compare, the measured impedances to evaluate the integrity of the lead. Instead of or in addition to withholding a shock, the IMD or another device may change a sensing or stimulation vector of the IMD, or provide an alert to a user, if the integrity test indicates a possible lead integrity issue.

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: 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: An implantable medical device (IMD) identifies suspected non-lethal ventricular arrhythmia, and takes one or more actions in response to the identification to avoid or delay delivery of a defibrillation or cardioversion shock. The IMD employs number of intervals to detect (NID) thresholds for detection of ventricular arrhythmias. When a NID threshold is met, the IMD determines whether the ventricular rhythm is a suspected non-lethal rhythm despite satisfying a NID threshold. In some embodiments, the IMD increases the NID threshold, i.e., extends the time for detection, in response to identifying a rhythm as a suspected non-lethal rhythm, and monitors subsequent ventricular beats to determine if the increased NID threshold is met before detecting a ventricular arrhythmia and delivering therapy. The IMD can determine whether a rhythm is a suspected non-lethal arrhythmia by, for example, comparing the median ventricular cycle length (VCL) to the median atrial cycle length (ACL).

Abstract: A physiological monitoring or therapy delivery system includes autonomous, wirelessly linked, implantable devices located at different areas to sense physiologic signals and deliver therapy. At least one of the implantable devices can trigger synchronized action (e.g. data capture or therapy delivery) by other implantable devices via a telemetry link.

Abstract: An implantable medical device (IMD) system includes an IMD, a transceiver antenna lead for the IMD, and a wireless therapy delivery transponder or probe that is remotely activated by the IMD via the transceiver antenna lead. The IMD and the wireless probe communicate using wireless RF-based transponder techniques. The wireless probe includes a capacitor that is charged when the IMD emits an appropriate electromagnetic field from the transceiver antenna lead. The wireless probe delivers electrical therapy in the form of electrical pulses from the capacitor in response to RF activation signals emitted by the IMD via the transceiver antenna lead.

Abstract: An elongate body of a medical electrical lead includes at least one conductor formed into a coil that includes a first portion and a second portion, wherein the first portion extends within an outer insulation sheath and the second portion extends outside the outer insulation sheath to be exposed to an environment external to the lead body as an energy dissipating shunt.

Abstract: An implantable medical device monitors ST segment data collected from EGM. ST trends are established and monitored over time. The IMD is able to discern whether the data indicate supply ischemia, demand ischemia, or other physiological causes. The IMD is then able to provide appropriate information and alerts.

Abstract: An implantable pressure sensor, which may be incorporated within an implantable medical electrical lead, includes an insulative sidewall, which contains a gap capacitor and an integrated circuit. The insulative sidewall of the pressure sensor includes a pressure sensitive diaphragm portion, and the gap capacitor includes a first electrode plate, which is attached to an interior surface of the diaphragm portion of the sidewall, and a second electrode plate, which is spaced apart from the first electrode plate and coupled to the integrated circuit, which is coupled, through the sidewall, to a supply contact and a ground contact. A conductive layer extends over one of the interior surface of the diaphragm portion of the sidewall and an exterior surface of the diaphragm portion; and the conductive layer is coupled to the ground contact to either shield or ground the first electrode plate.

Abstract: Data is communicated from a transmitter of an external unit to a receiver of an implantable medical device. The receiver of the implantable medical device operates in a wide band receiver mode to detect the transmission from the external unit and operates in a narrow band receiver mode to receive the data.

Abstract: A medical device capable of delivering automatic rate-adjusting pacing therapies is provided having an adjustable upper rate limit responsive to an indication of myocardial irritability. The device, which may be embodied as a pacemaker, a pacemaker/cardioverter/defibrillator, or the like, responds to the detection of an arrhythmia as an indicator of myocardial irritability by adjusting an upper rate limit. The adjusted upper rate limit is applied as the maximum allowable pacing rate during delivery of any pacing therapies previously defined as “long-term” pacing therapies.

Abstract: A medical device having a diode configuration in a lead assembly that substantially reduces induced currents in a lead assembly and at a tissue interface. The diodes configure an electrical path such that a stimulation pulse travels from the medical device to a selected tissue, and a current induced by an external changing electromagnetic signal is reduced and/or prevented from travelling the electrical path from the selected tissue to the medical device. The diodes may be at least partially contained in an electrode of the medical device.

Abstract: A medical apparatus includes a medical assist device to process signals to relating biological functions. A first lead is operatively connected to the medical assist device, the first lead having a distal end and a proximal end. A second lead is operatively connected to the medical assist device, the second lead having a distal end and a proximal end. The first electrode is operatively connected to the distal end of the first lead, and a second electrode is operatively connected to the distal end of the second lead. A filter circuit is operatively connected near the distal end of the first lead and the distal end of the second lead. A compensation circuit, operatively connected to the first lead, provides a compensation voltage to enable the filter to effectively block changing magnetic fields induced current in the second lead from passing through the second electrode of the distal end of the second lead.

Abstract: An electromagnetic interference immune defibrillator lead has a first electromagnetic insulating layer. A first layer is formed on the first electromagnetic insulating layer, the first layer having a plurality of first conductive rings composed of first conductive material, each first conductive ring being separated by first insulating material. A second electromagnetic insulating layer is formed on the first layer. A second layer is, formed on the second electromagnetic insulating layer, the second layer having a plurality of second conductive rings composed of second conductive material, each second conductive ring being separated by second insulating material. A third electromagnetic insulating layer is formed on the second layer. The second conductive rings of second conductive material are positioned such that a second conductive ring overlaps a portion of a first conductive ring and overlaps a portion of a second conductive ring, the second conductive ring being adjacent to the first conductive ring.

Abstract: An implantable medical device (IMD) includes a lead status monitoring system. The lead status monitoring system employs a method including the steps of: collecting data sets from a lead impedance source, a stimulation threshold source, and at least one additional source included in the IMD; and processing the data sets to determine if a lead status event has occurred.

Abstract: An implantable medical device (IMD) system includes an IMD, a transceiver antenna lead for the IMD, and a wireless therapy delivery transponder or probe that is remotely activated by the IMD via the transceiver antenna lead. The IMD and the wireless probe communicate using wireless RF-based transponder techniques. The wireless probe includes a capacitor that is charged when the IMD emits an appropriate electromagnetic field from the transceiver antenna lead. The wireless probe delivers electrical therapy in the form of electrical pulses from the capacitor in response to RF activation signals emitted by the IMD via the transceiver antenna lead.