Abstract: A closed system such as a TET system in which self-testing of all components of the implantable medical device whose malfunction could negatively impact on the proper operation of the closed system is automatically and periodically performed without triggering from an external device. In addition, a closed system including automatic, periodic self-testing of the implantable medical device in which, whenever practical, testing of the components is synchronized with telemetric communication of the external device whereby an external RF field generated by the external device is used to supply necessary power to perform self-testing.

Abstract: Automatic resetting of a group of multiple processors in an electronic device wherein the processors are arranged in either a cascade chain or master-slave configuration. Upon the receipt of an originating reset signal by any one of the multiple processors the remaining processors are reset upon receipt of a forced reset signal generated by one of the processors in the group. The system states prior to the originating reset of each processor is refreshed to ensure compatible synchronization of system states and thus proper communication among the processors.

Abstract: Methods and devices are described for monitoring reservoir fluid in an implantable infusion pump. Such methods and devices can be used when the infusion pump has a temperature-dependent component. For example, a method of monitoring reservoir fluid can include obtaining measurements from the reservoir that include corresponding data related to the amount of fluid and temperature in the reservoir. A pair of measurements can be used to monitor the fluid level, or flow rate out of, the reservoir when the corresponding temperatures of the measurements are within a temperature tolerance value. In such an instance, a measured amount difference can be calculated based on the fluid amounts corresponding to the pair of measurements. Other variations of fluid monitoring methods, and implantable infusion pump systems that can perform fluid monitoring, are also described.

Abstract: Continuous phase frequency shift keying modulation is employed during wireless transmission from an internal device to an external device to increase robustness of transmissions. The continuous phase frequency shift keying processor receives as input an incoming data stream and includes a timer for toggling its output between a first predetermined frequency and a second predetermined frequency on a predetermined time period basis based on the logical state of each bit in the incoming data stream. For a portion of time while the counter or timer of the CPFSK processor is counting down the predetermined time period associated with the detected logic state of a particular bit of the incoming data signal at least some of the other circuitry, preferably all of the other circuitry of the processor, is toggled to a sleep mode in which power is cut off thereby minimizing power consumption by the processor during this interim state.

Abstract: An implantable pump includes a base plate and a can that are parts of the pump housing. The base plate bottom divides the housing into a first electronics chamber and a second chamber. A bellows mechanism is connected to the base plate and is disposed within the second chamber. The bellow mechanism has an expandable sidewall and a bottom plate. The bellow mechanism divides the second chamber into a medicament receiving portion and a non-medicament-receiving portion. The bellow mechanism has an intermediate plate disposed within the medicament-receiving portion. A coil is disposed in a recess on the lower surface of the base plate, and the coil is spaced from an internal wall of the recess. The amount of fluid remaining in the implantable pump can be monitored by energizing the coil. A primary magnetic field is generated by the energized coil.

Abstract: Circuitry for conserving power in a system employing multiple electronic components of which a first electronic component operates at a first frequency and is continuously powered on by a power source. The system further includes a second electronic component operating at a second frequency different than that of the first frequency of the first electric component, the second electronic component being maintained in a powered off state in which no energy whatsoever is consumed by the second electronic component until energized in response to a power enabling signal generated by the first electronic component based on demand of the particular function to be performed by the second electronic component. The first and second electronic components may be processors, wherein the frequency of the first processor is lower than that of the second processor.

Abstract: A wireless communication system with power regulation feedback for improving the robustness of wireless communication transmissions between a receiver and an active emitter irrespective of the distance separation therebetween. The receiver receives wireless communications and detects a voltage induced therein. A feedback loop provides wireless transmission of power regulation feedback based on the detected voltage. The active emitter generates a power regulated data signal in which at least one of maximum and minimum bit voltage levels of respective logical high and low bits is adjusted based on the induced voltage received via the feedback loop. The RF power level, modulation index, and/or slew rate of a data signal emitted from the active emitter is regulated by adjusting at least one of maximum and minimum bit voltage levels of respective logical high and low bits based on voltage induced in the receiver during a previous communication from the active emitter.

Abstract: Circuitry for automatically powering on and maintaining activation of a powered down electronic component in a first device in RF communication with a second device, wherein the first and second devices are preferably an implantable medical device and an external control device, respectively. The system including power logic circuitry for generating a power on signal to automatically close a switch and energize an otherwise powered off electronic device when the power induced in the first device by external RF energy transmitted in the RF communication signal exceeds a minimum operating threshold of the power on logic circuitry. The electronic component while powered by the power source generates a hold signal and a second power signal that is transmitted to the power on logic circuitry to sustain power to the electronic component irrespective of interruptions of relatively short duration for less than a predetermined period of time in RF communication.

Abstract: A telemetry system including a first device having a processor that employs a DC balanced encoding scheme to generate a DC balanced encoded data signal, a modulator for modulating an RF carrier wave by the DC balanced encoded data signal and generating a DC balanced encoded RF modulated data signal including DC balanced RF energy. The DC balanced encoded RF modulated data signal transmitted by the first device is received by a second device. Since the RF energy received is DC balanced, drift in baseline voltage is eliminated irrespective of data transmission thereby improving the robustness of recovery of data by the second device. The second device may include a converter for converting the DC balanced RF energy extracted from the received DC balanced encoded RF modulated data signal to a substantially constant average induced voltage, irrespective of data being transmitted, for powering at least one component of the second device.

Abstract: A closed system such as a TET system in which self-testing of all components of the implantable medical device whose malfunction could negatively impact on the proper operation of the closed system is automatically and periodically performed without triggering from an external device. In addition, a closed system including automatic, periodic self-testing of the implantable medical device in which, whenever practical, testing of the components is synchronized with telemetric communication of the external device whereby an external RF field generated by the external device is used to supply necessary power to perform self-testing.

Abstract: Optimal power switching circuitry for use in a closed system such as a TET system including an internal device separated from an external device by a boundary. The internal and external devices being powered by separate power sources. During telemetric communication from the external device to the internal device an external RF energy source is produced. If the power supplied by the external RF energy source produced during communication from the external device to the internal device exceeds that required for powering of the internal device, then the power switching circuitry cuts off power to the internal power source and instead draws power from the external RF energy source thereby conserving power consumed from the internal power source. The power switching circuitry may be implemented using either passive components (e.g., diodes) or active components (e.g., an analog switch).

Abstract: A thermal flow sensor has a first, second and third substrate, each having a first side and a second opposite side. The first substrate is connected to the second substrate such that the second side of the first substrate abuts the first side of the second substrate. The third substrate is connected to the second substrate such that the second side of the second substrate abuts the first side of the third substrate. The second substrate has a groove formed therein so as to form a conduit bounded by the second substrate and the second side of the first substrate and the first side of the third substrate. The conduit has a fluid flow direction. A heater is disposed on the first side of the first substrate opposed to the conduit. A first temperature sensor is disposed on the first side of the first substrate opposed to the conduit and at a first predetermined distance from the heater in a direction opposite to the fluid flow direction.

Abstract: A remotely controlled gastric band system that is practically immune to external magnetic fields, such as from a Magnetic Resonance Imaging (MRI) machine, incorporates a bi-directional pump and fluid reservoir to adjust fluid volume for hydraulic control of a gastric band. A piezoelectric driver (e.g., rotary actuator, linear actuator) selectively compresses and expands a metal bellows hermetically sealed within a biocompatible and nonferromagnetic enclosure or case such as titanium. Directly sensing a position of the metal bellows yields an accurate reading of volume contained therein, allowing for closed-loop control of the gastric band.