Cordis Corporation

Other

Chester D Slocum, Jr

John Robert Batty, Jr

Vincent T Cutolo, Jr

For inbound data transmission a carrier signal is gated by the external programmer to transmit bursts of discrete numbers of cycles. The carrier is picked up by an implanted telemetry coil. The bursts are amplified and decoded by 'missing pulse' detection. Outbound telemetry is synchronized with the external constant carrier in a similar manner by loading the coil for discrete numbers of cycles. In the preferred embodiment, within an eight cycle bit period, two cycles of 64 kHz carrier represent '0' while a six cycle burst represents '1', to achieve a two-way data transmission rate of 8000 bits per second.

Biomedical implant with high speed, low power two-way telemetry

A system and process are provided for commanding a device implanted in a patient from an external command unit. A selected routine to be generated in response to a command signal from the external command unit is stored. A first access signal is transmitted from the command unit to the implant, to enable a computer within the implant to receive a command signal. A command signal is transmitted, from the command unit, to operate the selected routine. The operation of the selected routine is inhibited unless both the first access signal and the command signal have been generated.

System and process for enabling a predefined function within an

An analog data transmission circuit for a biomedical implant employs a linear amplifier to modulate the impedance of a resonant circuit tuned to an externally generated constant carrier frequency. The resonant circuit comprises a tuned coil in circuit with a linear modulating switch and a digital modulating switch. The digital switch is gated by the digital data output from digital control circuitry within the implant. The linear amplifier output drives the linear modulation switch. The switches are preferably matched pairs of MOSFET's of opposite polarity having complementary parasitic diodes which form a phantom diode bridge. The bridge acts as a full wave rectifier and boosts the bias voltage on the sources of the FET pair forming the linear modulation switch such that the radiated amplitude is independent of the distance of the programming head. A timed power-up circuit supplies power to the amplifier and starts a square wave calibration period in response to the approach of the programming head. For ICEG transmission, a charge dump circuit depolarizes the lead before it is coupled to the amplifier.

Analog telemetry system for biomedical implant

An apparatus and a process are disclosed for communicating an electrogram from a patient. An enclosure having a tuned coil mounted therein is implanted in the patient. The tuned coil is adapted to reradiate a signal in the presence of an externally generated carrier signal. A variable impedance device is provided across the tuned coil. The resistance of the variable impedance device can be altered linearly and it is set at a reference level that is approximately the center of its linear range. An analog signal, representative of the electrogram, is coupled to the input of the variable impedance device. In this manner, the variable impedance device will be modulated in response to the electrogram.

Apparatus and process for communicating an electrogram

An externally generated myriametric frequency magnetic carrier signal is resonantly reflected by a tuned coil in an implant. The lagging phase angle of the reflected signal is modulated at very low power by varying the impedance across the tuned coil in accordance with a data input signal. An external phase shift demodulator recovers the transmitted data. To assure adequate coupling between the external unit and the implant, the output level of an external phase comparator must exceed a given threshold to signify 'acquisition' before data is transmitted from the implant. In a preferred embodiment, a shunt circuit across the tuned coil is opened and closed in accordance with a digital input signal generated by the implant. The external telemetry unit preferably includes a coaxially spaced triple coil assembly. The middle coil transmits the carrier. The outer pickup coils are balanced to minimize carrier reception. For two-way communication an IR transmitter is added to the coil assembly. During acquisition, the output of the tuned coil is used to turn on a dormant IR receiver in the implant. Light emitting diodes are preferably mounted in an array on the face of the coil assembly surrounded by an optional reed switch coil for multimode telemetry in the programmer.

Implant telemetry system

A shunted coil telemetry transponder in an implant is employed as a magnetic pulse transducer for receiving externally transmitted data. Additional circuitry reproduces the pulse waveform from inductive spikes and interfaces a programming data input with an auxiliary reed switch used for the diagnostic mode.

Programming and telemetry system for biomedical implantable device

An electrical storm forecast system includes a sensor unit for receiving electrostatic field information, an amplitude and phase detector coupled to the sensor unit and information processing means coupled to the amplitude phase detector.

Growing community of inventors

Miami, FL, United States of America

Chester D Slocum, Jr