Systems and methods for measurement of heart rate and other heart-related characteristics from photoplethysmographic (PPG) signals using collision computing
In a noninvasive system for measurement of heart rate and other heart-related characteristics a photoplethysmogram (PPG) obtained from a tissue is divided into several feature waveforms, each corresponding to a PPG window of a particular length. Conditioned features, containing frequency components specific to heart-related events, are derived from the features by modulating a carrier kernel with such features. The conditioned features are computationally collided with one or more Zyotons that are co-dependent with the conditioned features. For each conditioned feature, one or more collisions selectively amplify frequency components in features sourced from PPG, and respective energy change values are obtained from such amplified energy portions. The resulting energy change values are analyzed to determine a smallest time-window likely containing heart rate and other heart-related events in the PPG data stream. Over time, the detected events are grouped and analyzed to determine heart rate and other heart-related characteristics.
1. A method for generating features for measurement of heart-beat rate, the method comprising:
receiving a signal based on one of reflected and transmitted radiation from a tissue during a global time interval starting at a global start time and ending at a global end time;
designating, via a processor, a first portion of the signal starting at the global start time and ending at a first end time less than the global end time as a first feature;
designating, via the processor, a second portion of the signal starting at the global start time and ending at a second end time greater than the first end time as a second feature; and
displaying the heart-beat rate computed using the first and second features.
2. The method of claim 1 , further comprising:
determining that an expected end of a heart-beat cycle is absent within the first portion of the signal, designated as the first feature; and
designating the first feature as a non-analyte feature.
3. The method of claim 2 , further comprising:
determining that the expected end of the heat-beat cycle is present within the second portion of the signal, designated as the second feature; and
designating the second feature as an analyte feature.
4. The method of claim 3 , further comprising determining the heart-beat rate by:
colliding a first conditioned feature waveform derived from the first feature with a co-dependent Zyoton to obtain a first energy change;
colliding a second conditioned feature waveform derived from the second feature with a co-dependent Zyoton to obtain a second energy change;
computing an end of the heart-beat cycle using the first and second energy changes; and
computing the heart-beat rate using the start of the heart-beat cycle and the end of the heart-beat cycle.
5. A system for generating features for measurement of heart-beat rate, the system comprising:
a first processor; and
a first memory in electrical communication with the first processor, the first memory comprising instructions which, when executed by a processing unit comprising at least one of the first processor and a second processor, and in electronic communication with a memory module comprising at least one of the first memory and a second memory, program the processing unit to:
receive a signal based on one of reflected and transmitted radiation from a tissue during a global time interval starting at a global start time and ending at a global end time;
designate a first portion of the signal starting at the global start time and ending at a first end time less than the global end time as a first feature;
designate a second portion of the signal starting at the global start time and ending at a second end time greater than the first end time as a second feature; and
display the heart-beat rate computed using the first and second features.
6. The system of claim 5 , wherein the instructions further program the processing unit to:
determine that an expected end of a heart-beat cycle is absent within the first portion of the signal, designated as the first feature; and
designate the first feature as a non-analyte feature.
7. The system of claim 6 , wherein the instructions further program the processing unit to:
determine that the expected end of the heat-beat cycle is present within the second portion of the signal, designated as the second feature; and
designate the second feature as an analyte feature.
8. The system of claim 7 , wherein to determine the heart-beat rate, the instructions further program the processing unit to:
collide a first conditioned feature waveform derived from the first feature with a co-dependent Zyoton to obtain a first energy change;
collide a second conditioned feature waveform derived from the second feature with a co-dependent Zyoton to obtain a second energy change;
compute an end of the heart-beat cycle using the first and second energy changes; and
compute the heart-beat rate using the start of the heart-beat cycle and the end of the heart-beat cycle.