Pulse to sinewave telemetry system
First Claim
1. A telemetry system for communicating with a tank circuit contained in a pacer implanted in a patient comprising:
- a telemetry coil being positionable externally on the patient'"'"'s skin in proximity to the implanted pacer;
capacitive means connected to said telemetry coil for forming a resonant tank;
said resonant tank having a varying impedance in response to telemetered digital data signals from the implanted tank circuit;
clocking means for generating a squarewave at a selected frequency;
delayed clock-to-pulse converter means responsive to said squarewave for generating drive pulses which are slightly delayed from the leading edges of said squarewave;
coil driver means for generating a sinusoidal carrier waveform having a varying amplitude and frequency in response to the drive pulses and to the varying impedance of said resonant tank;
means for sampling each cycle of the sinusoidal carrier wave of varying amplitude and frequency to provide a sample and hold signal; and
output means coupled to said sampling means for recovering of the telemetered digital data signals in the form of a binary pulse-width modulated signal.
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Accused Products
Abstract
A telemetry system for communicating with a tank circuit contained in a pacer implanted in a patient includes a telemetry coil and a capacitor connected to the telemetry coil for forming a resonant tank. The telemetry coil is positionable externally on the patient'"'"'s skin substantially overlying the implanted pacer. The resonant tank has a varying impedance in response to telemetered digital data signals from the implanted tank circuit. A clock oscillator generates a squarewave at a selected frequency. A delayed clock-to-pulse converter is responsive to the squarewave for generating drive pulses which are slightly delayed from the leading edges of the squarewave. A coil driver generates a sinusoidal carrier waveform having a varying amplitude and frequency in response to the drive pulses and to the varying impedance of the resonant tank. A sample and hold circuit is provided for sampling each cycle of the sinusoidal carrier waveform of the varying amplitude and frequency to provide a sample and hold signal. An output circuit is coupled to the sample and hold circuit for recovering of the telemetered digital data signal in the form of a binary pulse-width modulated signal.
42 Citations
20 Claims
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1. A telemetry system for communicating with a tank circuit contained in a pacer implanted in a patient comprising:
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a telemetry coil being positionable externally on the patient'"'"'s skin in proximity to the implanted pacer; capacitive means connected to said telemetry coil for forming a resonant tank; said resonant tank having a varying impedance in response to telemetered digital data signals from the implanted tank circuit; clocking means for generating a squarewave at a selected frequency; delayed clock-to-pulse converter means responsive to said squarewave for generating drive pulses which are slightly delayed from the leading edges of said squarewave; coil driver means for generating a sinusoidal carrier waveform having a varying amplitude and frequency in response to the drive pulses and to the varying impedance of said resonant tank; means for sampling each cycle of the sinusoidal carrier wave of varying amplitude and frequency to provide a sample and hold signal; and output means coupled to said sampling means for recovering of the telemetered digital data signals in the form of a binary pulse-width modulated signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. In a telemetry system for pacing in which a pacer containing a data modulated tank circuit is implanted in a patient and a programming and telemetry unit is used external of the patient, the improvement comprising in combination:
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a telemetry coil being positionable externally on the patient'"'"'s skin in proximity to the implanted pacer; capacitive means connected to said telemetry coil for forming a resonant tank; said resonant tank having a varying impedance in response to telemetered digital data signals from the implanted tank circuit; clocking means for generating a squarewave at a selected frequency; delayed clock-to-pulse converter means responsive to said squarewave for generating drive pulses which are slightly delayed from the leading edges of said squarewave; coil driver means for generating a sinusoidal carrier waveform having a varying amplitude and frequency in response to the drive pulses and to the varying impediance of said resonant tank; means for sampling each cycle of the sinusiodal carrier wave of varying amplitude and frequency to provide a sample and hold signal; and output means coupled to said sampling means for recovering of the telemetered digital data signals in the form of a binary pulse-width modulated signal. - View Dependent Claims (14, 15, 16, 17, 18)
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19. A system for detecting proximity of an external program and telemetry unit with respect to an implanted pacer comprising:
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a telemetry coil being positionable externally on the patient'"'"'s skin in proximity to the implanted pacer; capacitive means connected to said telemetry coil for forming a resonant tank; said resonant tank having a varying impedance in response to telemetered digital data signals from the implanted tank circuit; clocking means for generating a squarewave at a selected frequency; delayed clock-to-pulse converter means responsive to said squarewave for generating drive pulses which are slightly delayed from the leading edges of said squarewave; coil driver means for generating a sinusoidal carrier waveform having a varying amplitude and frequency in response to the drive pulses and to the varying impedance of said resonant tank; means for sampling each cycle of the sinusoidal carrier wave of varying amplitude and frequency to provide a sample and hold signal; and acquisition means responsive to said sample and hold signal to produce a pulse train having a varying frequency which increases as the distance of the telemetry coil to the implanted pacer deceases. - View Dependent Claims (20)
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Specification