Abstract: Systems and methods for efficiently transmitting power using a high frequency (e.g., RF) telemetry transmitter are provided. The telemetry transmitter may include a fixed clock source (which may provide a fixed clock signal), telemetry phase shift circuitry (which may include switching circuitry and phase shifting circuitry), and a push-pull network. The telemetry phase shift circuitry generates a phase shifted clock signal that is phase shifted with respect to the fixed clock signal. The fixed and phase shifted clock signals may drive the switching circuitry to produce a high frequency signal that is passed through the push-pull network. The power or magnitude of the high frequency signal is based on the phase delay between the fixed clock signal and the phase shifted clock signal.

Abstract: An implantable neural stimulation system, such as an auditory Fully Implantable System (FIS), includes: (1) an implanted device capable of providing desired tissue or nerve stimulation; and (2) a remote control unit that provides a mechanism for readily controlling the implant device. The remote control unit uses a first signal path to send signals to the implant device, and a second signal path to receive signals from the implant device. The combination of these two signal paths provides a full-duplex channel between the remote control unit and the implant device through which appropriate control and status signals may be sent and received. In one embodiment, the first signal path comprises an audio signal path through which audio control signals, e.g., a tone sequence or a 32-bit word FSK modulated between 300 and 1200 Hz, are sent; and the second signal path comprises a RF signal path through which a BPSK, QPSK or FM modulated RF signal is received.

Abstract: A method of controlling an implantable neural stimulation system, such as an auditory Fully Implantable System (FIS), uses a first signal path to send signals to the implant device, and a second signal path to receive signals from the implant device. The combination of these two signal paths provides a full-duplex channel between the remote control unit and the implant device through which appropriate control and status signals may be sent and received. In one embodiment, the first signal path comprises an audio signal path through which audio control signals, e.g., a tone sequence or a 32-bit word FSK modulated between 300 and 1200 Hz, are sent; and the second signal path comprises a RF signal path through which a BPSK, QPSK or FM modulated RF signal is received. The full-duplex channel allows operation of the remote control unit, i.e., allows signals to be successfully sent to and received from the implant device, from as far away as 45–60 cm from the implant device.

Abstract: A fully implantable cochlear prosthesis includes (1) an implantable hermetically sealed case wherein electronic circuitry, including a battery and an implantable microphone, are housed, (2) an active electrode array that provides a programmable number of electrode contacts through which stimulation current may be selectively delivered to surrounding tissue, preferably through the use of appropriate stimulation groups, and (3) a connector that allows the active electrode array to be detachably connected with the electronic circuitry within the sealed case. The active electrode array provides a large number of both medial and lateral contacts, any one of which may be selected to apply a stimulus pulse through active switching elements included within the array. The active switching elements included within the array operate at a very low compliance voltage, thereby reducing power consumption.

Abstract: A cochlear implant system is provided that does not require a headpiece. Rather, the external coil used to transfer power and data and control signal to the implant device is integrated into the housing of the external processor. In one embodiment, where the external processor is carried within a behind-the-ear (BTE) module that is worn by a user of the cochlear implant system, the external coil is carried within the BTE module or housing, or formed as part of the ear hook used to hold the BTE module in place. Because the external transfer coil forms an integral part of the external portion of the system, the present invention does not require the use of an implanted magnet. Hence, the cochlear implant system can be described as headpieceless and magnetless (e.g., including a single external device).

Abstract: An implantable neural stimulation system, such as an auditory Fully Implantable System (FIS), includes: (1) an implanted device capable of providing desired tissue or nerve stimulation; and (2) a remote control unit that provides a mechanism for readily controlling the implant device, i.e., for selectively adjusting certain stimulation parameters associated with the tissue stimulation of the implanted device. The remote control unit uses a first signal path to send signals to the implant device, and a second signal path to receive signals from the implant device. The combination of these two signal paths provides a full-duplex channel between the remote control unit and the implant device through which air appropriate control and status signals may be sent and received. In one embodiment, the first signal path comprises an audio signal path through which audio control signals, e.g.

Abstract: A fully implantable cochlear prosthesis includes (1) an implantable hermetically sealed case wherein electronic circuitry, including a battery and an implantable microphone, are housed, (2) an active electrode array that provides a programmable number of electrode contacts through which stimulation current may be selectively delivered to surrounding tissue, preferably through the use of appropriate stimulation groups, and (3) a connector that allows the active electrode array to be detachably connected with the electronic circuitry within the sealed case. The active electrode array provides a large number of both medial and lateral contacts, any one of which may be selected to apply a stimulus pulse through active switching elements included within the array. The active switching elements included within the array operate at a very low compliance voltage, thereby reducing power consumption.

Abstract: A fixed frequency external power source having an external coil is inductively coupled with an implanted coil of an implanted medical device. The implant device has an electronic impedance transformer as part of its load circuit. Such electronic impedance transformer sets a proper voltage and current ratio (impedance) so that the coil set, i.e., the external coil and the implanted coil, are loaded with an optimal load. Such optimal loading, in turn, significantly minimizes any mismatch loss from the inductive link between the external coil and the implant coil, and allows wide ranges in the voltage and load resistance and coil separation, while at the same time maintaining an optimal load condition. The impedance transformer is especially applicable to fully implantable cochlear stimulation systems wherein, during one mode of operation, a relatively large power level must be transferred for charging the implanted power storage element, e.g.

Abstract: A fully implantable cochlear prosthesis includes (1) an implantable hermetically sealed case wherein electronic circuitry, including a battery and an implantable microphone, are housed, (2) an active electrode array that provides a programmable number of electrode contacts through which stimulation current may be selectively delivered to surrounding tissue, preferably through the use of appropriate stimulation groups, and (3) a connector that allows the active electrode array to be detachably connected with the electronic circuitry within the sealed case. The active electrode array provides a large number of both medial and lateral contacts, any one of which may be selected to apply a stimulus pulse through active switching elements included within the array. The active switching elements included within the array operate at a very low compliance voltage, thereby reducing power consumption.

Abstract: A spiral shield for an implantable secondary coil confines the electrical field of the coil, and thus prevents capacitive coupling of the coil through surrounding dielectrics (such as human tissue.) Known implantable devices receive power inductively, through a secondary coil, from a primary coil in an external device. Efficient power reception requires that the coils be tuned to the same resonant frequency. Use of the spiral shield results in predictable electrical behavior of the secondary coil and permits the secondary coil to be accurately tuned to the same resonate frequency as the primary coil. To further improve performance, spacers made from SILBIONE®LSR 70 reside between turns of the coil to reduce turn to turn and turn to shield capacitances. Reducing the capacitances prevents excessive reduction of the self resonant frequency of the coil. The coil is imbedded in SILBIONE®LSR 70, allowing for a thin and flexible coil.

Abstract: A fully implantable cochlear prosthesis includes (1) an implantable hermetically sealed case wherein electronic circuitry, including a battery and an implantable microphone, are housed, (2) an active electrode array that provides a programmable number of electrode contacts through which stimulation current may be selectively delivered to surrounding tissue, preferably through the use of appropriate stimulation groups, and (3) a connector that allows the active electrode array to be detachably connected with the electronic circuitry within the sealed case. The active electrode array provides a large number of both medial and lateral contacts, any one of which may be selected to apply a stimulus pulse through active switching elements included within the array. The active switching elements included within the array operate at a very low compliance voltage, thereby reducing power consumption.

Abstract: An external power transfer circuit (12) couples ac power having a fixed frequency into an implantable electrical circuit (14), e.g., an implantable tissue stimulator, while automatically maintaining optimum power transfer conditions. Optimum power transfer conditions exist when there is an impedance match between the external and implanted circuits. The external transfer circuit includes a directional coupler (42) and an impedance matching circuit (44). The directional coupler senses the forward power being transferred to the implant device, as well as the reverse power being reflected form the implant device (as a result of an impedance mismatch). The impedance matching circuit includes at least one variable element controlled by a control signal.

Abstract: An implantable medical device, such as an implantable cochlear stimulator (ICS) system, utilizes laminated, sectionalized or particle-ized permanent magnets and/or keepers in both the implant portion and external (non-implanted) portion so as to reduce the electrical energy absorbed by both the implant device and the external device when in use. In one embodiment, the implant device employs a sectionalized, laminated or particle-based “keeper”, while the external device employs a sectionalized, laminated or particle-ized magnet, making the implant device immune to being damaged by MRI (magnetic resonance imaging).

Abstract: An efficient RF telemetry transmitter system includes a first stage and a second stage. The transmitter system sends power and data to an implant device using pulse-width modulation of a high fixed frequency clock signal, e.g., a 49 MHz clock signal, within the first stage in order to provide efficient generation of an RF output signal in the second stage. Digital logic gates and related circuitry, e.g., implemented in an application specific integrated circuit (ASIC), are used in the first stage to provide pulse-width modulation of the fixed frequency clock signal in order to optimally set the drive level of the output signal of the first stage, or inter-stage signal. ON/OFF keying, or other modulation scheme, further modulates the clock signal with data in the first stage. The second stage includes a Class-E amplifier circuit implemented with a single RF transistor, biased with a temperature-compensated offset voltage set just below the cut-off voltage of the transistor.

Abstract: A discharge-excited waveguide gas laser is disclosed utilizing a transverse rf excitation voltage at a frequency of at least about 30 MHz applied between elongated electrodes on opposite sides of the laser discharge chamber. A plurality of shunt inductances are coupled between the electrodes externally of the chamber at periodically spaced locations along the length of the chamber. These inductances provide a negative admittance which compensates for the variation in the phase angle of the transmission line reflection coefficient along the length of the laser discharge chamber. The variation in the magnitude of the standing wave voltage produced in the chamber by the excitation voltage is reduced accordingly, thereby improving the uniformity of the laser-exciting discharge.

Abstract: The present invention is an improved drum mechanism for use in combination with an automatic photographic processing system which includes a housing, a bi-directional motor that has a shaft and that is mounted on the housing, a control unit for controlling the bi-directional motor and a drain tray that is mounted on the housing. The automatic photographic processing system also includes a fluid injector unit for injecting fluids into said improved drum mechanism that is electrically coupled to the control unit and that is mounted on the housing.

Abstract: In this monophonic pedal or truncated decay system, depression of a new pedal key immediately truncates tone production of a previously played, decaying note. If two notes are played simultaneously, both will sound until one is released, whereupon that tone will be truncated immediately without decay.The inventive system operates with a time-shared electronic musical instrument wherein selected keys are assigned to respective time slots in a repetitive timing interval. During each such interval, a first flip-flop is set by occurrence of the first assigned pedal key. A second flip-flop cooperates with the first flip-flop, and is set during each time interval by occurrence of a second assigned pedal key. A third flip-flop is set at the end of each timing interval to copy the contents of the second flip-flop. The third flip-flop thus provides, during the subsequent timing interval, a signal indicating that two or more pedal keys are being played.