Wearable athletic monitoring using digital modulation

A method for generating and processing tissue-monitoring signals,

• the method comprising:
• providing an optical-electronic device, the optical-electronic device including:
• at least two optical emitters including a first emitter and a second emitter;
• an optical emitter driver operably coupled with the at least two optical emitters;
• a processor coupled with the at least two optical emitters;
• a photodetector, wherein each of the at least two optical emitters are at different distances from the photodetector, wherein the second emitter is located between the first emitter and the photodetector;
• and
• a hardware processing sequence coupled to the photodetector and processor;
• generating, by the processor, at least one emitted signal for each of the at least two optical emitters;
• receiving, at the optical emitter driver, each of the at least one emitted signal;
• controlling, by the optical emitter driver upon receipt of each of the at least one emitted signal, each of the at least two optical emitters to emit the at least one emitted signal;
• detecting, at the photodetector, one or more photons transmitted through tissue from each of the first emitter and the second emitter;
• converting, at the photodetector, the detected photons into a detected signal;
• filtering and conditioning, at the hardware processing sequence, the detected signal;
• demodulating, at the processor, each of the at least one emitted signal and the detected signal by cross-correlating each of the at least one emitted signal and the detected signal;
• determining, at the processor, an amplitude of a correlation peak given by the cross-correlation of each of the at least one emitted signal and the detected signal;
• modifying, at the processor, the amplitude of the correlation peak by adjusting a time-bandwidth product of the at least one emitted signal;
• wherein each of the at least one emitted signal is at least one broadband signal.

A system operable to generate and process tissue-monitoring

• signals, comprising:
• two or more optical emitters including a first emitter and a second emitter, each of the optical emitters operable to emit at least two emitted signals;
• a processor coupled to the two or more optical emitters;
• a photodetector operable to detect one or more photons transmitted through tissue from each of the first emitter and the second emitter and to convert the detected one or more photons into a detected signal, wherein each of the two or more optical emitters are at different distances from the photodetector, wherein the second emitter is located between the first emitter and the photodetector;
• and
• a hardware processing sequence coupled to the photodetector and the processor and operable to filter and condition the detected signal;
• wherein the processor is operable to execute instructions to demodulate the at least two emitted signals and the detected signal by cross-correlating each of the at least two emitted signal and the detected signal;
• wherein each of the at least two emitted signals are at least one broadband signal,
• wherein the processor is further operable to execute instructions to determine an amplitude of a correlation peak given by the cross-correlation of each of the at least two emitted signals and the detected signal;
• wherein the amplitude of the correlation peak is operable to be modified by adjusting a time-bandwidth product of the emitted signal.