AM/FM multi-channel implantable/ingestible biomedical monitoring telemetry system

A system for propagating a plurality of signals indicative of physiological stimuli from a point inside a human body to a point external to the body comprising:

• a. first sensor means responsive to a first physiological stimulus for producing a first signal;
• b. second sensor means responsive to a second physiological stimulus for producing a second signal;
• c. a first oscillator modulated by said first signal and having a frequency depending on the instantaneous amplitude of said first signal;
• d. a second oscillator modulated by said second signal and having a frequency dependent on the instantaneous amplitude of said second signal;
• e. said first and second oscillators having two different subcarrier frequencies;
• f. means for summing the output signals of said oscillators thereby producing a third signal;
• g. temperature responsive means for independently of said first and second oscillators producing a fourth signal which varies in frequency as a function of body temperature;
• h. modulator means coupled to the outputs of said summing means and said temperature responsive means for modulating said fourth signal by said third signal thereby producing a fifth signal which contains information of said first, second, and fourth signals;
• i. means for propagating said fifth signal to a point external of said human body;
• and
• j. a receiver means intercepting said fifth signal and including:
• A. means for producing a replica of said fourth signal;
• B. first demodulator means for detecting the FM signals produced by said first and second oscillators;
• D. second demodulator means coupled to said first demodulator means for demodulating said FM signals;
• and
• D. filter means coupled to said second demodulator means for receiving said first and second signals.

A system for propagating a plurality of signals indicative of physiological signals from a point inside a human body to a point external to the body comprising:

• a. first op-amp means responsive to a first physiological stimulus for producing a first signal;
• b. second op-amp means responsive to a second physiological stimulus for producing a second signal;
• c. a first oscillator modulated by said first signal and having a frequency dependent on the instantaneous amplitude of said first signal;
• d. a second oscillator modulated by said second signal and having a frequency dependent on the instantaneous amplitude of said second signal;
• e. said first and second oscillators having two different subcarrier frequencies;
• f. shaping means coupled to each of said oscillators for attenuating the odd harmonics present in the frequency modulated (FM) outputs of said first and second oscillators;
• g. means for summing the output signals of said shaping means thereby producing a third signal;
• h. temperature responsive means for independently of said first and second oscillators producing a fourth signal which varies as a function of temperature;
• i. modulator means coupled to the outputs of said summing means and said temperature responsive means for modulating said fourth signal as a function of said third signal thereby producing a fifth signal which contains information of said first, second, and fourth signals;
• j. means for propagating said fifth signal to a point external of said human body;
• and
• k. receiver means intercepting said fifth signal for separating said first, second, and fourth signals from each other thereby providing means for indicating said physiological stimuli and said body temperature.

A system for propagating a plurality of signals indicative of measurable variables from an enclosure:

• a. first sensor means responsive to a first measurable variable for producing a first signal;
• b. second detector means responsive to a second measurable variable for producing a second signal;
• c. a first oscillator modulated by said first signal and having a frequency dependent on the instantaneous amplitude of said first signal;
• d. a second oscillator modulated by said second signal and having a frequency dependent on the instantaneous amplitude of said second signal;
• e. said first and second oscillators having two different subcarrier frequencies;
• f. means for summing the output signals of said oscillators thereby producing a third signal;
• g. temperature responsive means for independently of said first and second oscillators producing a fourth signal which varies in frequency as a function of temperature;
• h. modulator means coupled to the outputs of said summing means and said temperature responsive means for modulating said second signal as a function of said third signal thereby producing a fifth signal which contains information of said first, second, and fourth signals.
• i. means for propagating said fifth signal to a point external of said human body;
• and
• j. receiver means intercepting said fifth signal for separating said first, second, and fourth signals from each other thereby providing means for indicating said first and second measured variables and said temperature.