Medtronic, Inc.

Charles H Dudding

Javaid Masoud

Gregory John Haubrich

George C Rosar

Quentin Scott Denzene

David Jerome Peichel

Steven D Goedeke

Len D Twetan

Eric D Corndorf

Nicholas C Wine

Robert S Wentink

Remi Le Reverend

Guy A Delight

Andrew Michael Bottomley

Philip Dorning

Peter Bradley

Robert A Patrias

An implantable medical device ('IMD') as described herein includes an adjustable data retransmission scheme, which controls the manner in which data is retransmitted by the IMD. The retransmission feature can be adjusted in a dynamic manner based upon the type, context, or meaning of the telemetry data transmitted by the IMD. The IMD may process contextual meaning information that influences its data retransmission configuration. Such adjustability enables the IMD to satisfy minimum telemetry requirements in a manner that does not waste power, thus extending the IMD battery life.

Implantable medical device with variable data retransmission characteristics based upon data type

An implantable medical device ('IMD') as described herein includes adjustable power characteristics such as variable transmitter output power and variable receiver front end gain. These power characteristics can be adjusted in a dynamic manner based upon various operating aspects of the intended or actual IMD telemetry environment. These operating aspects may include the external telemetry device type, the IMD device type, and/or the type, context, or meaning of the telemetry data transmitted by the IMD. The IMD may process information related to these operating aspects to generate power scaling instructions or control signals that are interpreted by the IMD transmitter and/or the IMD receiver. Such adjustability enables the IMD to satisfy minimum telemetry requirements in a manner that does not waste power, thus extending the IMD battery life.

Variable implantable medical device power characteristics based upon data or device type

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.

System and method for unscheduled wireless communication with a medical device

A low power multiple channel receiver mixing architecture for detecting wake-up signals over multiple communication channels in sniff processing performed in an implantable medical device (IMD). The architecture includes a direct conversion real receiver configured to scan a selected center channel and a Weaver receiver configured in parallel to the direct conversion real receiver to simultaneously scan side channels, together simultaneously detecting whether a wake-up signal is being received over the center and side channels with minimal power consumption. The architecture further utilizes a falsing protection algorithm that reduces power consumption during sniff operations by inhibiting the sniffing of channels likely to provide a false indication of a wake-up signal based the presence of unwanted signals on those channels. The falsing protection algorithm restricts those channels from sniff processing likely to provide a false indication of a wake-up signal, such that sniff processing can aborted, prevented, limited or otherwise altered to conserve power consumption.

Low power multiple channel mixing architecture for detecting wake-up signals and related falsing protection algorithm

Embodiments of the invention include channel selection and mapping for medical device communication. The communication system can implement a two-stage listen before talk protocol to choose a channel for communication. The first stage samples the interference of each channel for a relatively short time and chooses the best signal. The second stage samples the channel selected by the first stage and samples it for a relatively longer time to confirm the channel selected by the first stage is the best channel for communication.

Channel selection and mapping for medical device communication

An implantable medical device (IMD) includes a telemetry module to communicate with an external device according to a given protocol. To establish a communication session, the IMD will extend active periods of reception on a given channel when some confirmed data is received from the external device. In addition, once a session has been opened, the programmer transmits a short data set (or preamble) for each cycle which the IMD is set to receive. This data set indicates whether additional data will or will not be sent. If no additional data is to be sent during that cycle, then the IMD powers down the receiver for that cycle.

System and method for telemetry with an implantable medical device

An implantable medical device ('IMD') as described herein includes adjustable power characteristics such as variable transmitter output power and variable receiver front end gain. These power characteristics are adjusted based upon the intended or actual implant depth of the IMD. The IMD may process an IMD implant depth value (provided by an external IMD programming device) to generate power scaling instructions or control signals that are interpreted by the IMD transmitter and/or the IMD receiver. Such adjustability enables the IMD to satisfy minimum telemetry requirements in a manner that does not waste power, thus extending the IMD battery life.

Variable implantable medical device power characteristics based upon implant depth

Uplink and downlink telemetry between an implantable medical device (IMD) telemetry transceiver and an external medical device (EMD) telemetry transceiver used by a patient or health care provider is facilitated by the communications system of the present invention. The IMD provides a therapy and/or measures physiologic conditions of the patient for use in formulating a therapy and/or for storage in IMD memory for later uplink telemetry transmission. The patient causes the EMD to emit encoded dual tone multiple frequency (DTMF) tones that are detected by an audio receiver of the IMD to enable uplink and downlink telemetry transmissions in a telemetry or communication session. Then, the patient formulates a message via a message entry mechanism of the EMD that communicates an instruction or query to the IMD. The downlink message is optionally displayed by an EMD display as it is composed by the user and is then downlink telemetered to the IMD. A responsive uplink message from the IMD is uplink telemetered, received by the EMD telemetry transceiver, stored in EMD memory and displayed by EMD display. The EMD optionally includes a DSVD/modem module for either connection to a telephone line or a cellular telephone receiver in a variety of ways that can provide two-way voice communication between the patient and a remote care provider as well as transmission of uplink telemetered IMD and patient data to a remote EMD. The IMD may further include an audio tone generator for generating a tone or series of tones indicative of operation or status of the IMD that can be heard by the patient or received and displayed by the IMD. The DTMF tones can also be employed to alter an IMD operation.

Method and apparatus for communicating with an implantable medical device with DTMF tones

In an implantable medical device, a frequency synthesizer employed in the RF transceiver of the IMD operating system functions in a PLL LOCK mode wherein the VCO frequency is governed by the PLL and an energy saving HOLD mode wherein the PLL is not operational and the VCO generated carrier frequency can drift over time. The PLL circuit is powered up and coupled with a control voltage input and the output of the VCO to develop a frequency control voltage stored by a capacitive loop filter during initial LOCK portions of both uplink and downlink telemetry transmission time periods. A frequency modulation (FM) input of the VCO receives data bit modulation voltages that modulates the carrier frequency during uplink transmission of patient data. During the HOLD portion of a downlink telemetry transmission, an AFC algorithm is enabled and derives a frequency correction value from the difference in frequency of the constant received carrier frequency and the drifting VCO generated carrier frequency, and the frequency correction value is applied to the VCO FM input to compensate for loop filter capacitor discharge of the control voltage causing the drift. The AFC algorithm derived frequency correction value is stored in memory and is also applied during the HOLD portion of an uplink telemetry transmission to the VCO FM input to compensate for loop filter capacitor discharge of the control voltage causing the drift. In addition, a recharge current is applied to the capacitive loop filter.

Low energy consumption RF telemetry control for an implantable medical device

An implantable medical device and a method of operation thereof. The implantable device includes apparatus for delivering a therapy to a patient or monitoring a physiologic parameter of a patient and control circuitry for modifying operation of the device. The device further includes an audio receiver responsive to sequences of DTMF tones and coupled to the control circuitry, which modifies the operation of the device responsive to received DTMF tone sequences. The device preferably includes a telemetry system and the control circuitry may modify operation of the telemetry system responsive to received DTMF tone sequences. In addition or alternatively, the control circuitry may modify operation of the apparatus for delivering a therapy to a patient or monitoring a physiologic parameter responsive to received DTMF tone sequences. The device may further include an audio tone generator for generating a tone or series of tones indicative of operation or status of the device.

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Lino Lakes, MN, United States of America

Charles H Dudding