Pulse to sine wave/sample decoder telemetry system
First Claim
1. A telemetry system for communicating with a tank circuit contained in a pacer implanted in a patient comprising:
- 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 data signals from the implanted tank circuit;
clocking means for generating drive current pulses at a selected frequency to be applied to said resonant tank;
switching means for generating a pulse waveform having a varying amplitude and frequency in response to the drive current pulses and to the varying impedance of said resonant tank;
means sampling the pulse waveform 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 data signals in the form of a binary pulse-width modulated signal.
9 Assignments
0 Petitions
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 inpedance in response to telemetered data signals from the implanted tank circuit. A clock oscillator generates drive current pulses at a selected frequency to be applied to the resonant tank. A switching transistor generates a pulse waveform having a varying amplitude and frequency in response to the drive current pulses and to the varyng impedance of the resonant tank. A pair of sample and hold circuits are connected in series to function as a clocked filter for sampling the pulse waveform of a varying amplitude and frequency to provide a sample and hold signal. An output circuit is coupled to the sample and hold circuits for recovering of the telemetered data signals in the form of a binary pulse-width modulated signal.
14 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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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 data signals from the implanted tank circuit; clocking means for generating drive current pulses at a selected frequency to be applied to said resonant tank; switching means for generating a pulse waveform having a varying amplitude and frequency in response to the drive current pulses and to the varying impedance of said resonant tank; means sampling the pulse waveform 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 data signals in the form of a binary pulse-width modulated signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. In a telemetry system for pacing in which a pacer containing a data modulated tank circuit is implanted in a patient and a program and telemetry unit is used external of the patient, the improvement comprising in combination:
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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 data signals from the implanted tank circuit; clocking means for generating drive current pulses at a selected frequency to be applied to said resonant tank; switching means for generating a pulse waveform having a varying amplitude and frequency in response to the drive current pulses and to the varying impedance of said resonant tank; means sampling the pulse waveform 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 data signals in the form of a binary pulse-width modulated signal. - View Dependent Claims (12, 13, 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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telemetry coil being positionable externally on the patient'"'"'s skin substantially overlying 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 data signals from the implanted tank circuit; clocking means for generating drive current pulses at a selected frequency to be applied to said resonant tank; switching means for generating a pulse waveform having a varying amplitude and frequency in response to the drive current pulses and to the varying impedance of said resonant tank; means sampling the pulse waveform of varying amplitude and frequency to provide a sample and hold signal; and an offset tracking filter being responsive to said sample and hold signal to provide a DC signal level representative of the distance of the telemetry coil to the implanted pacer. - View Dependent Claims (20)
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Specification