Abstract: A device, such as an IMD, having a tissue conductance communication (TCC) transmitter controls a drive signal circuit and a polarity switching circuit by a controller of the TCC transmitter to generate an alternating current (AC) ramp on signal having a peak amplitude that is stepped up from a starting peak-to-peak amplitude to an ending peak-to-peak amplitude according to a step increment and step up interval. The TCC transmitter is further controlled to transmit the AC ramp on signal from the drive signal circuit and the polarity switching circuit via a coupling capacitor coupled to a transmitting electrode vector coupleable to the IMD. After the AC ramp on signal, the TCC transmitter transmits at least one TCC signal to a receiving device.

Abstract: A device, such as an IMD, having a tissue conductance communication (TCC) transmitter controls a drive signal circuit and a polarity switching circuit by a controller of the TCC transmitter to generate an alternating current (AC) ramp on signal having a peak amplitude that is stepped up from a starting peak-to-peak amplitude to an ending peak-to-peak amplitude according to a step increment and step up interval. The TCC transmitter is further controlled to transmit the AC ramp on signal from the drive signal circuit and the polarity switching circuit via a coupling capacitor coupled to a transmitting electrode vector coupleable to the IMD. After the AC ramp on signal, the TCC transmitter transmits at least one TCC signal to a receiving device.

Abstract: A method and apparatus related to detecting the presence of a power transfer coil implanted in a patient are disclosed. According to the aspect, an external device of a medical implant system is provided, the external device having an external coil and processing circuitry. The processing circuitry is configured to monitor a resonance frequency associated with the external coil. When the resonance frequency changes as a distance between the external coil and an expected location of an internal coil, then the processing circuitry is configured to conclude that the internal coil has been detected. When the resonance frequency ramps up to a steady state value at a rate that falls below a rate threshold, then the processing circuitry is configured to conclude that the internal coil is connected to an internal load.

Abstract: A method of managing multiple power sources for an implantable blood pump includes operating the implantable blood pump with both power from an internal battery, the internal battery being disposed within an implantable controller and in communication with the implantable blood pump, and with transcutaneous energy transfer system (TETS) power in communication with the implantable blood pump, if TETS power is available.

Abstract: In an implanted medical device system, an internal controller, external power transmitter and methods for regulation of TETS power for an implanted medical device system are disclosed. According to one aspect, a method in an external power transmitter of an implanted medical device system includes determining a current in an external coil of the external power transmitter, multiplying the determined current by a supply voltage to determine a power delivered to the external coil, and controlling the power delivered to the external coil by adjusting the current in the external coil.

Abstract: The present disclosure provides a transcutaneous energy transfer system (TETS), having an implantable receiving coil in communication with an implantable controller and a hermetically sealed package encased by the implantable receiving coil. The hermetically sealed package including a plurality of tuning capacitors, at least one temperature sensor, scavenging circuitry configured to scavenge power from the plurality of tuning capacitors, and a temperature measuring circuit in communication with the at least one temperature sensor and the scavenging circuitry. The at least one temperature sensor being configured to measure a temperature of the hermetically sealed package and the temperature measuring circuit being configured to transmit the measured temperature to the implantable controller.

Abstract: In an implanted medical device system, an internal controller, external power transmitter and methods for monitoring and dynamically managing power in an implanted medical device system are disclosed. According to one aspect, an internal controller is configured to provide power to a motor of an implanted medical device, the power being drawn from at least one of an internal battery and an internal coil, the at least one of the internal battery and the internal coil providing a supplied voltage. The internal controller includes processing circuitry configured to switch to one of the internal battery, the internal coil and a combination of the internal battery and the internal coil, based on a comparison of the supplied voltage to a threshold.

Abstract: In an implanted medical device system, an external power transmitter and methods for adjusting a rate of search pulse transmission by an external power transmitter of an implanted medical device system are disclosed. According to one aspect, a method includes detecting a condition of the external power transmitter, and selecting among rates of transmission of search pulses based on the detected condition.

Abstract: An internal controller and an external power transmitter of an implanted medical device system and method therefore are provided. According to one aspect, an external power transmitter as part of a implanted medical device system includes processing circuitry configured to detect a shunting condition of an internal coil of the implanted medical device system, and responsive to detecting a shunting condition, reduce a magnitude of power transmitted to the internal coil.

Abstract: An internal coil interface implantable within the body of a patient and configured to modulate a load on an internal coil, and a method therefore are provided. According to one aspect, processing circuitry of the internal coil interface is configured to predict a time of a first voltage level crossing by a voltage at a terminal of the internal coil for each of a plurality of successive windows each time the capacitance is switched into the modulated load circuit or each time the capacitance is switched out of the modulated load circuit. The process is also configured to adjust the predictions based on whether a previous prediction of a time of a first voltage level crossing for a window was later or earlier than a time at which the first voltage level crossing actually occurred.

Abstract: A method of estimating power dissipated by a foreign metallic object in a transcutaneous energy transfer system (TETS) includes estimating power loss between an external coil of the TETS and an implanted coil of the TETS using a transfer function, the transfer function including inputs, the inputs including: a power supplied to the external coil, a power received by the implanted coil, a measured current within the external coil, and a carrier frequency between the external coil and the implanted coil and generating an alert if the estimated power loss between the external coil and the implanted coil exceeds a predetermined threshold.

Abstract: A method of managing multiple power sources for an implantable blood pump includes operating the implantable blood pump with both power from an internal battery, the internal battery being disposed within an implantable controller and in communication with the implantable blood pump, and with transcutaneous energy transfer system (TETS) power in communication with the implantable blood pump, if TETS power is available.

Abstract: A digitally timed complementary metal oxide semiconductor (CMOS) rectifier for wireless power transfer in an implanted medical device is provided. According to one aspect, a voltage rectification circuit for a medical device having an internal coil and internal circuitry includes a voltage rectifier comprising a complementary metal oxide semiconductor (CMOS) circuit having low-side first type MOS transistors and upper cross-coupled second type MOS transistors. The voltage rectifier may be configured to output a rectified received voltage, each low-side first type MOS transistor being configured with an first type MOS body diode, the low-side first type MOS transistors being enabled by a timing signal to provide conduction through the low-side first type MOS transistors while bypassing conduction through the first type MOS body diode during a time window having a duration determined by voltage level crossings of the received voltage.

Abstract: A system, such as an IMD system, includes a tissue conductance communication (TCC) transmitter configured to generate a beacon signal by generating a carrier signal and modulating a first property of the carrier signal according to a first type of modulation. The TCC transmitter is configured to generate a data signal subsequent to the beacon signal by generating the carrier signal and modulating a second property of the carrier signal different than the first property according to a second type of modulation different than the first type of modulation.

Abstract: A device is configured to transmit tissue conductance communication (TCC) signals by generating multiple TCC signals by a TCC transmitter of the IMD. The generated TCC signals are coupled to a transmitting electrode vector via a coupling capacitor to transmit the plurality of TCC signals to a receiving medical device via a conductive tissue pathway. A voltage holding circuit holds the coupling capacitor at a DC voltage for a time interval between two consecutively transmitted TCC signals.

Abstract: A controller implantable within the body of a patient as part of a left ventricular assist device (LVAD) system and a method therefore are provided. According to one aspect, the controller includes processing circuitry configured to determine a voltage difference by determining a difference between a first voltage obtained from an internal coil of the controller and a target voltage, and is further configured to encode the voltage difference to produce an encoded voltage difference message. The internal coil is configured to transmit the encoded voltage difference message to a power transmitter to enable closed loop control of power transfer from the power transmitter to the controller to drive the voltage difference toward zero.

Abstract: A device, such as an IMD, having a tissue conductance communication (TCC) transmitter controls a drive signal circuit and a polarity switching circuit by a controller of the TCC transmitter to generate an alternating current (AC) ramp on signal having a peak amplitude that is stepped up from a starting peak-to-peak amplitude to an ending peak-to-peak amplitude according to a step increment and step up interval. The TCC transmitter is further controlled to transmit the AC ramp on signal from the drive signal circuit and the polarity switching circuit via a coupling capacitor coupled to a transmitting electrode vector coupleable to the IMD. After the AC ramp on signal, the TCC transmitter transmits at least one TCC signal to a receiving device.

Abstract: A method and apparatus related to detecting the presence of a power transfer coil implanted in a patient are disclosed. According to the aspect, an external device of a medical implant system is provided, the external device having an external coil and processing circuitry. The processing circuitry is configured to monitor a resonance frequency associated with the external coil. When the resonance frequency changes as a distance between the external coil and an expected location of an internal coil, then the processing circuitry is configured to conclude that the internal coil has been detected. When the resonance frequency ramps up to a steady state value at a rate that falls below a rate threshold, then the processing circuitry is configured to conclude that the internal coil is connected to an internal load.

Abstract: A device includes a tissue conduction communication (TCC) transmitter that generates a TCC signal including a carrier signal having a peak-to-peak amplitude and a carrier frequency cycle length including a first polarity pulse for a first half of the carrier frequency cycle length and a second polarity pulse opposite the first polarity pulse for a second half of the carrier frequency cycle length. Each of the first polarity pulse and the second polarity pulse inject a half cycle charge into a TCC pathway. The TCC transmitter starts transmitting the TCC signal with a starting pulse having a net charge that is half of the half cycle charge and transmits alternating polarity pulses of the carrier signal consecutively following the starting pulse.

Abstract: According to one or more embodiments, a system is provided. The system includes a power device implantable within a patient for powering an implantable medical device. The power device includes a first coil configured to receive wireless power signals for powering the implantable medical device and processing circuitry configured to determine at least one measurable electrical characteristic in a plurality of electrical pathways in the power device including an electrical pathway to the first coil, and detect reduced performance in receiving wireless power signals based at least in part on the determined at least one measurable electrical characteristic.