Abstract: An implantable medical device (IMD) that can be wirelessly connected to user interface by which a patient can enter values of selected control parameters for controlling the IMD whereas other control parameters are not accessible via said user interface and can only be modified by a physician or other authorized personnel.

Abstract: Disclosed is a remote controller for an implantable medical device having stored contraindication information, which includes information which a patient or clinician might wish to review when assessing the compatibility of a given therapeutic or diagnostic technique or activity with the patient's implant. The stored contraindication information is available through a display of the remote controller or via a wired, wireless, or portable drive connection with an external device. By storing contraindication information with the implant's remote controller, patient and clinician can more easily determine the safety of a particular therapeutic or diagnostic technique or physical activity with the patient's implant, perhaps without the need to contact the manufacturer's service representative.

Abstract: Channel assessment and selection for wireless communication is made between two or more medical devices, such as between an implantable medical device (IMD) and a non-implanted medical device, between two IMDs, or between two non-implanted medical devices. A telemetry module of a medical device operating in accordance with the techniques of this disclosure obtains measured ambient power levels on a plurality of channels of a frequency band regulation, such as the ten channels of the MICS band regulation. The telemetry module computes channel assessment values for at least a portion of the plurality of channels based on the measured ambient power levels on at least one other channel of the plurality of channels and selects a channel to transmit on based on the channel assessment values.

Abstract: A medical device communication system includes a receiver adapted to receive radio frequency (RF) signals and configured to operate in a first mode to poll for an RF signal for a first time interval to detect an element of a valid input signal during the first time interval. In response to detecting the element of a valid input signal in the first time interval, the receiver operates in a second mode to poll for the RF signal for a second time interval to analyze the RF signal over the second time interval to detect a valid modulation of the RF signal. In response to detecting a valid modulation of the RF signal during the second time interval, the receiver is enabled to establish a communication session with a transmitting device.

Abstract: A communication device for an implantable medical device may include: an input/output interface configured to communicate with a wireless communication device; a communication interface configured to communicate with a remote system; and a processor configured to perform an analysis of data received from the wireless communication device via the input/output interface and associated with the implantable medical device. The communication device may include a user interface configured to receive data input by a user. A communication system may include a wireless communication device and the aforementioned communication device.

Abstract: A method comprises connecting at least one portion of a far-field radio-frequency (RF) first telemetry circuit in an implantable medical device to an energy source through a power connection module, detecting information included in a first predetermined wireless signal, changing a conductivity state of the power connection module when the information in the first predetermined wireless signal is detected to couple power to the at least one portion of the first telemetry circuit, detecting a second predetermined wireless signal, and changing a conductivity state of the power connection module to decouple power to the at least one portion of the first telemetry circuit when the second predetermined wireless signal is detected and the first telemetry circuit enters an idle state.

Abstract: Controlling the interaction between an external device and an implanted device, including a method of controlling interaction between an external device and an implanted device, the method including at least the steps of: establishing communications between the implanted device and the external device; the external device determining an identification of the implant and comparing the identification with identifications in a stored list; if the device matches one of said identifications, then using a corresponding set of operating parameters to interact with said implant; and otherwise, not interacting with said device.

Abstract: Apparatus for monitoring vital signs of one or more living subjects comprises a monitoring station and at least one sensor in communication with the monitoring station. The sensor comprises an antenna system, an ultra wideband radar system coupled to the antenna system, a signal processor and a communication system. The signal processor is connected to receive a signal from the ultra wideband radar system and configured to extract from the signal information about one or more vital signs of a person or animal in a sensing volume corresponding to the antenna system. The communication system is configured to transmit the information to the monitoring station.

Abstract: This disclosure describes a chopper mixer telemetry circuit for use in a wireless receiver. The receiver may be located in an implantable medical device (IMD) or external programmer. The chopper mixer telemetry circuit may include a mixer amplifier that operates as a synchronous demodulator to provide selective extraction of wireless signals received from a transmitter while suppressing out-of-band noise that can undermine the reliability of the telemetry link between an IMD or programmer and another device. The mixer amplifier may utilize parallel signal paths to convert the received telemetry signal into an in-phase (I) signal component and a quadrature (Q) signal component and recombine the I and Q signal components to reconstruct the total signal independently of the phase mismatch between the transmitter and receiver. Each signal path may include a chopper-stabilized mixer amplifier that amplifies telemetry signals within a desired band while suppressing out-of-band noise.

Abstract: Systems and methods for temporarily pacing a patient's heart are provided. One system includes a hemostasis valve with an adjustable electrical connection, the adjustable electrical connection having one or more adjustable contacts. The adjustable contacts have a first, radially expanded configuration and a second, radially constricted configuration. In the radially constricted configuration, the adjustable contacts are configured to pierce through a layer of an elongate medical device that is disposed in the hemostasis valve. The elongate medical device has a distal electrode and a conductor extending along a portion of the elongate medical device. The adjustable contacts pierce through a make contact with the conductor, providing an electrical pathway to the distal electrode. Also provided are vascular access systems including a hemostasis valve and a guide catheter, guide wire torquers with adjustable contacts and methods of temporarily pacing a patient's heart.

Abstract: A data collection system collects and stores physiological data from an ambulatory patient at a high resolution and/or a high data rate (“more detailed data”) and sends a low-resolution and/or downsampled version of the data (“less detailed data”) to a remote server via a wireless network. The server automatically analyzes the less detailed data to detect an anomaly, such as an arrhythmia. A two-tiered analysis scheme is used, where the first tier is more sensitive and less specific than the second tier. If the more sensitive analysis detects or suspects the anomaly, the server signals the data collector to send more detailed data that corresponds to a time period associated with the anomaly. The more specific second tier analyses the more detailed data to verify the anomaly. The server may also store the received data and make it available to a user, such as via a graphical or tabular display.

Abstract: A neural prosthesis includes a centralized device that can provide power, data, and clock signals to one or more individual neural prosthesis subsystems. Each subsystem may include a number of individually addressable, programmable modules that can be dynamically allocated or shared among neural prosthetic networks to achieve complex, coordinated functions or to operate in autonomous groups.

Abstract: In an example, an apparatus can include an implantable medical device comprising a housing, an implantable telemetry circuit carried within the housing, a dielectric compartment mechanically coupled to the housing, the dielectric compartment including first and second substantially parallel face portions and a third face portion extending between the first and second face portions, and an implantable telemetry antenna, located at least partially within the dielectric compartment. The implantable telemetry circuit can be electrically coupled to the implantable telemetry antenna and configured to wirelessly transfer information electromagnetically using the implantable telemetry antenna. In an example the implantable telemetry antenna comprises a spiral conductor portion extending along the first, second, and third face portions. In an example the spiral conductor includes a cross section having a lateral width that can be greater than a sidewall height of the cross section.

Abstract: An improved external charger for an implantable medical device is disclosed in which charging is at least partially controlled based on a sensed pressure impingent on its case, which pressure is indicative of the pressure between the external charger and a patient's tissue. The improved external charger includes pressure detection circuitry coupled to one or more pressure sensors for controlling the external device in accordance with the sensed impingent pressure. The sensed pressure can be used to control charging, for example, by suspending charging, by adjusting a maximum set point temperature for the external charger based on the measured pressure, or by issuing an alert via a suitable user interface. By so controlling the external charger on the basis of the measured pressure, the external charger is less likely to create potentially problematic or uncomfortable conditions for the user.

Abstract: Techniques associated with a universal recharging device for recharging a power source of implantable medical devices (IMDs). The recharging device includes an interface to allow an antenna assembly to be removably coupled. The antenna assembly has a primary coil and a corresponding sense coil. The sense coil has a configuration that is selected based on the configuration of the primary coil. The sense coil is adapted to prevent voltage across the primary coil from exceeding a maximum voltage amplitude allowable with the recharging device. The maximum voltage amplitude may be selected based on a maximum magnetic field strength to which a patient is to be exposed. In one embodiment, the maximum voltage amplitude is programmable.

Abstract: An exemplary method includes a sound processing unit 1) directing an implantable cochlear stimulator to apply a plurality of stimulation pulses each having a first pulse width by way of a plurality of electrodes during a first stimulation frame, the plurality of electrodes including a first electrode and a set of remaining electrodes, 2) detecting a change in impedance of the first electrode, 3) adjusting, in response to the change in impedance of the first electrode, a pulse width parameter associated with the first electrode to define a second pulse width, and 4) directing the implantable cochlear stimulator to apply a stimulation pulse having the second pulse width by way of the first electrode and a plurality of stimulation pulses having the first pulse width by way of the set of remaining electrodes during a second stimulation frame subsequent to the first stimulation frame.

Abstract: An implantable electrostimulation assembly, including an electrostimulation device and an electrode lead that is connected to the electrostimulation device when in use, wherein the electrode lead has an optically readable electrode identification and a cable adapter is provided for the temporary insertion between the electrostimulation device and the electrode lead, the adapter comprising optical read means for reading the electrode identification and transmission means for transmitting the same to the electrostimulation device and/or to an assembly-external receiver.

Abstract: A data collection system collects and stores physiological data from an ambulatory patient at a high resolution and/or a high data rate (“more detailed data”) and sends a low-resolution and/or downsampled version of the data (“less detailed data”) to a remote server via a wireless network. The server automatically analyzes the less detailed data to detect an anomaly, such as an arrhythmia. A two-tiered analysis scheme is used, where the first tier is more sensitive and less specific than the second tier. If the more sensitive analysis detects or suspects the anomaly, the server signals the data collector to send more detailed data that corresponds to a time period associated with the anomaly. The more specific second tier analyses the more detailed data to verify the anomaly. The server may also store the received data and make it available to a user, such as via a graphical or tabular display.

Abstract: An ambulatory monitoring device includes a sensor to monitor a physiological signal and a battery power source. The device also includes a wireless transceiver adapted to monitor a first frequency band having frequencies below 1 MHz and configured to detect and receive, using less than 10 micro-amps of current from the battery power source when operating, wireless communications within the first frequency band from a remote device at least one meter away. The wireless transceiver is further adapted to transmit—after receipt from the remote device of a first wireless communication within the first frequency band that includes an invitation for further communication—a second wireless communication in a second frequency band having frequencies above 10 MHz, the second wireless communication comprising data indicative of the physiological signal as sensed by the sensor.

Abstract: This disclosure describes techniques for obtaining an image of an anatomical implant region where leads associated with an implantable medical device are implanted in a patient, manipulating the image to show lead locations and placements, performing necessary image compression and manipulations, adjusting the image to associate it with information (e.g., patient, metadata, annotations, etc.) useful to a subsequent programmer retrieving the image, and transferring a copy of the captured image to the implantable medical device. The image stored in the implantable medical device may be retrieved at a later time by a user of programmer, where the user can use the image and other associated information to program subsequent therapy.

Abstract: An implantable medical device comprises a hermetically sealed housing having a housing wall with an interior surface, and an ultrasonic acoustic transducer, the transducer comprising one or more piezoelectric discs fixed to the interior surface of the housing wall, such that the housing wall acts as a diaphragm in response to induced movement by the one or more piezoelectric material discs.

Abstract: A wireless electrostimulation system can comprise a wireless energy transmission source, and an implantable cardiovascular wireless electrostimulation node. A receiver circuit comprising an inductive antenna can be configured to capture magnetic energy to generate a tissue electrostimulation. A tissue electrostimulation circuit, coupled to the receiver circuit, can be configured to deliver energy captured by the receiver circuit as a tissue electrostimulation waveform. Delivery of tissue electrostimulation can be initiated by a therapy control unit.

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 seed assembly for delivery to an interior of a heart includes an electrical stimulation circuit for delivering an electrical stimulus to cardiac tissue. A first electrode assembly is mechanically and electrically coupled to the seed assembly via a micro lead the first electrode assembly configured to deliver the electrical stimulus generated by the electrical stimulation circuit to the cardiac tissue. The seed assembly and the first electrode assembly are sized and shaped to fit entirely within the heart.

Abstract: An electrode stimulation delivery system is described having a unit and a network of wireless remote electrodes configured for implantation within a plurality of spaced apart locations in the tissue, e.g. myocardium, of a patient. The control unit is configured to be positioned at or subcutaneous to the patient's skin, and includes a processor, an antenna configured for delivering RF energy in proximity to the plurality of wireless remote electrodes, and programming executable on the processor for wirelessly communicating to the network of wireless remote electrodes via the delivered RF energy to individually control pacing of the plurality of wireless remote electrodes. Each of the plurality of wireless remote electrodes comprises a metamaterial-based biomimetic harvesting antenna comprising a Van Atta array zero-phase transmission lines to receive the RF energy to power activation of the plurality of wireless remote electrodes.

Abstract: Far field telemetry operations are conducted between an external device and an implantable medical device while power is being transferred to the implantable medical device for purposes of recharging a battery of the implantable medical device. The far field operations may include exchanging recharge information that has been collected by the implantable medical device which allows the external device to exercise control over the recharge process. The far field operations may include suspending far field telemetry communications for periods of time while power continues to be transferred where suspending far field telemetry communications may include powering down far field telemetry communication circuits of the implantable medical device for periods of time which may conserve energy. The far field operations may further include transferring programming instructions to the implantable medical device.

Abstract: A system and method for virtually detecting a medical condition, such as acute myocardial infarction (AMI), in a patient using holistic diagnostic procedures implemented in medical devices. Physiological parameters in a patient are monitored in an implantable medical device (IMD) to detect deviations from desired characteristics. When severe physiological parameter deviations exist indicating with a desired certainty that the patient is experiencing a medical condition (e.g., AMI), an alert is generated. If only minor deviations from the desired characteristics exist, additional holistic diagnostic procedures are performed virtually for diagnosing whether the patient is likely to be experiencing the medical condition, such as querying the patient through an external device regarding symptoms the patient is experiencing and analyzing the patient's responses to the questions to determine whether the patient is experiencing the medical condition.

Abstract: Physiological data is generated from signals received from one or more leads associated with the IMD. The physiological data is sampled to generate a plurality of data samples. A predictive encoding algorithm is applied to the plurality of data samples to generate a plurality of encoded data samples each corresponding to one of the plurality of data samples. An entropy encoding algorithm is then applied to the plurality of encoded data samples to generate a plurality of code words each corresponding to one of the plurality of encoded data samples. The code words are then stored in a memory in the IMD.

Abstract: A system and method for modifying the parameters of an implantable medical device includes an implantable medical device that communicates with a remote control device that, in turn, communicates through the browser of a computer or any other device capable of using mark-up language protocol. The computer optionally communicates with other computers and/or devices through a network.

Abstract: A programmer for an implantable medical device includes an adjustable kickstand. In one example, the kickstand is configured to combine with the base to support the programmer in an upright position when the kickstand is fully-collapsed to support the programmer in a reclined position when the kickstand is fully-extended. Further, the programmer housing may include a fan grate that allows airflow from a cooling fan to pass through the programmer housing. The fan grate is positioned behind the kickstand when the kickstand is in the fully-collapsed position. The kickstand includes an aperture adjacent the fan grate when the kickstand is in the fully-collapsed position, the aperture allowing airflow from the cooling fan to pass through the fan grate when the kickstand is in the fully-collapsed position.

Abstract: A system and method for managing locally-initiated medical device interrogation is presented. An interface is provided over which to retrieve patient data recorded and transiently staged by a medical device monitoring physiological measures of a patient. The patient data is periodically retrieved by interfacing to and interrogating the medical device per a pre-defined schedule through the interface. Further retrieval of the patient data is permitted independent of the pre-defined schedule. The system stores remotely-specifiable criteria specified by a caregiver and controls patient-initiated patient data retrieval in accordance with the criteria.

Abstract: System, telemetry head and method for programming an implantable medical device adapted to provide a therapeutic output to a patient, the implantable medical device being programmable through a telemetry interface. A telemetry head is adapted for transcutaneous communication with the implantable medical device through the telemetry interface when the telemetry head is positioned with respect to the implantable medical device. A computing device has computing processing power and a user interface linked with the telemetry head. The computing device processes the computing instructions associated with the implantable medical device. The computing device supplies the user interface based, at least in part, on the computing instructions associated with the implantable medical device. The telemetry head receives programming instructions from the computing device and provides the programming instructions to the implantable medical device using the transcutaneous telemetry interface.

Abstract: The present disclosure involves a charging system for charging an implanted medical system. The charging device includes a replenishable power supply. The charging device includes a coil assembly electrically coupled to the power supply. The coil assembly includes a primary coil and a plurality of sense coils positioned proximate to the primary coil. The charging device includes electrical circuitry operable to: measure an electrical parameter of the coil assembly; and determine a position of the coil assembly relative to a position of the implanted medical device based on the measured electrical parameter. The charging device includes a visual communications interface operable to: receive an input from the electrical circuitry; and visually display on a screen the position of the coil assembly relative to the position of the implanted medical device based on the input received from the electrical circuitry.

Abstract: An interface device for facilitating transfer of medical information between a patient implantable medical device (PIMD) and a remote network server via public network infrastructure is disclosed, the interface device using any of a plurality of generic network access devices having disparate communication protocols. First communication circuitry is configured to receive medical information from a patient implantable medical device (PIMD), and second communication circuitry configured to effect communication with the first communication circuitry and a generic network access device. A processor is coupled the first communication circuitry and the second communication circuitry. The processor is configured to control transmission of the medical information to the generic network access device and condition the medical device data in compliance with a predetermined medical information regulatory standard governing the PIMD. A method is also disclosed.

Abstract: A leadless intra-cardiac medical device comprises an integrated L-C resonant circuit pressure sensor. In some embodiments, the pressure sensor comprises a passive sensor that measures pressure in response to an externally generated excitation signal. In some embodiments, the pressure sensor comprises an active sensor that measures pressure in response to an internally generated excitation signal.

Abstract: By incorporating magnetic field sensing coils in an external charger, it is possible to determine the position of an implantable device by sensing the reflected magnetic field from the implant. In one embodiment, two or more field sensing coils are arranged to sense the reflected magnetic field. By comparing the relative reflected magnetic field strengths of the sensing coils, the position of the implant relative to the external charger can be determined. Audio and/or visual feedback can then be communicated to the patient to allow the patient to improve the alignment of the charger.

Abstract: An apparatus and method for adjusting the performance of an implanted device based on data including contextual information. Contextual information, including operational and performance data concerning the implanted device as well as the patient with the implanted device, is stored by a portable electronic device. In one embodiment, the portable electronic device is adapted for battery operation and includes a personal digital assistant (PDA). The portable electronic device is adapted for use as an interface to conduct wireless communications with the implanted device. In one embodiment, the portable electronic device interfaces with a clinical programmer for use by a physician.

Abstract: A system level scheme for networking of implantable devices, electronic patch devices/sensors coupled to the body, and wearable sensors/devices with cellular telephone/mobile devices, peripheral devices and remote servers is described.

Abstract: An external defibrillator can receive wirelessly a data signal transmitted by a transmitting device over a communication link. The defibrillator can include a processor configured to monitor a reception parameter of the communication link while the data signal is being received and to set an alert flag if the processor determines from the reception parameter that reception of the data signal may be discontinued prematurely. The defibrillator can also include a user interface capable of outputting an alerting user notification responsive to the alert flag being set.

Abstract: Techniques are disclosed for recharging an Implantable Medical Device (IMD). In one embodiment, a first external coil is positioned on one side of a patient's body, such as on a front side of the torso in proximity to the IMD. A second external coil is positioned on an opposite side of the patient's body, such as on the back of the torso. A recharging device generates a current in each of the coils, inductively coupling the first and the second coils to the secondary recharge coil of the IMD. According to another aspect, each of the two external coils may wrap around a portion of the patient's body, such as the torso or head, and are positioned such that the IMD lies between the coils. According to this aspect, current generated in the coils inductively couples to a second recharge coil that is angled within the patient's body.

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: Disclosed is an improved external controller useable in an implantable medical device system. The communication coil in the external controller is formed in a printed circuit board (PCB), i.e., by using the various tracing layers and vias of the PCB. As illustrated, the PCB coil is formed at a plurality of trace layers in the PCB, and comprises a plurality of turns at some or all of the layers. The communication coil may wrap around the other circuitry used in the external controller, which circuitry may be mounted to the front and/or back of the PCB. The geometry of the coil is specially tailored to maximize its inductance, and hence maximize its ability to communicate in the sub-4 MHz range which is not significantly attenuated by the human body.

Abstract: An ambulatory monitoring device includes a sensor to monitor a physiological signal and a battery power source. The device also includes a wireless receiver adapted to monitor a first frequency band having frequencies below 1 MHz and configured to detect and receive, using less than 10 micro-amps of current from the battery power source when operating, wireless communications within the first frequency band from a remote device at least one meter away. The device further includes a wireless transmitter adapted to transmit—after receipt from the remote device of a first wireless communication within the first frequency band that includes an invitation for further communication—a second wireless communication in a second frequency band having frequencies above 10 MHz, the second wireless communication comprising data indicative of the physiological signal as sensed by the sensor.

Abstract: A patient device (10) having a first interface (20) for the wireless transmission of data from and to an implant and having a second interface (22) for the remote data communication with a central service center and having a third interface (24) different from the first and second interfaces, the third interface (24) being implemented for connecting a programming device to the patient device (10) and the patient device (10) being implemented to relay programming data received via the third interface (24) on the part of a programming device to the first interface (20) and wirelessly transmit it to an implant.

Abstract: This document discusses, among other things, a modular antitachyarrhythmia therapy system. In an example, a modular antitachyarrhythmia system includes at least two separate modules that coordinate delivery an antitachyarrhythmia therapy, such as a defibrillation therapy. In another example, a modular antitachyarrhythmia therapy system includes a sensing module, an analysis module, and a therapy module.

Abstract: Devices and systems provide for proximity based selection of an implantable medical device for far field communication with an external device. By using a proximity communication that is limited to the IMD of interest during the selection process, the external device can eliminate those IMDs that are in range of far field communications but are able to receive the proximity communication. Thus, information may be shared via a proximity communication that is validated via a far field communication, or shared via a far field communication as a challenge and then validated via a proximity communication. The proximity communication may be used to initially limit the number of devices that respond to a discovery request and then subsequently used to select the intended implantable medical device as well as automatically select the appropriate therapy application corresponding to the selected IMD.

Abstract: An implantable cardiac tissue excitation system includes an implantable pacing controller unit with a pulse generation circuit. The system also includes a lead with a lead body extending between a proximal lead end attachable to the pacing controller unit and a distal lead end configured to be implanted within a heart. A lead conductor extends within the lead body. The system also includes a transmitter assembly located near the distal lead end that is electrically connected to the pulse generation circuit through the lead conductor to wirelessly transmit pacing control information and pacing energy. The system also includes a leadless electrode assembly configured to be implanted within the heart that includes a receiver to receive the wireless transmission, a charge storage unit to store the charge energy, and an electrical stimulation circuit to deliver an electrical stimulus to cardiac tissue using the pacing control information and the charge energy.

Abstract: A device includes a housing, a radio-frequency (RF) antenna, a ground plane, an inductive telemetry antenna, and a processing module. The RF antenna is associated with the housing. The ground plane of the RF antenna is within the housing. The inductive telemetry antenna is within the housing and is disposed over a portion of the ground plane. The processing module is within the housing and is configured to communicate with a medical device using at least one of the RF antenna and the inductive telemetry antenna.

Abstract: An improved external charger for an implantable medical device is disclosed in which charging is at least partially controlled based on a sensed pressure impingent on its case, which pressure is indicative of the pressure between the external charger and a patient's tissue. The improved external charger includes pressure detection circuitry coupled to one or more pressure sensors for controlling the external device in accordance with the sensed impingent pressure. The sensed pressure can be used to control charging, for example, by suspending charging, by adjusting a maximum set point temperature for the external charger based on the measured pressure, or by issuing an alert via a suitable user interface. By so controlling the external charger on the basis of the measured pressure, the external charger is less likely to create potentially problematic or uncomfortable conditions for the user.

Abstract: A telemetry system is presented for enabling wireless communications between an implantable medical device and an external device in a manner which reduces the power requirements of the implantable device by duty cycling its wireless communication circuitry. A wakeup scheme for the implantable device is provided in which the external device transmits a data segment containing a repeating sequence of special wakeup characters in order to establish a communications session with the implantable device. The wakeup scheme may be designed to operate in the context of a handshaking protocol for collision avoidance.