Biological tissue function analysis

1. A method for heart function analysis, comprising:

receiving, by a processor, patient signal data from a patient, the patient signal data including SPO2 signal data received from an oximeter and indicative of saturation of hemoglobin with oxygen and respiration signal data received from a respiratory monitor;

using a signal data analysis unit to synchronize the SPO2 signal data by gating the SPO2 signal using the respiration signal to select a first cycle of the SPO2 signal which corresponds to exhalation of the patient and a second cycle of the SPO2 signal which corresponds to inspiration of the patient;

determining, by the processor, one or more waveform parameters based on the selected cycles of the synchronized SPO2 signal data;

determining, by the processor, one or more respiration-SPO2 parameters based on the one or more waveform parameters;

determining a heart function based on the one or more respiration-SPO2 parameters; and

generating a patient report indicating the determined heart function.

2. The method of claim 1 wherein determining the one or more waveform parameters comprises extracting morphology information associated with the synchronized SPO2 signal.

3. The method of claim 2 wherein extracting the morphology information comprises detecting peaks or valleys of a waveform within the synchronized SPO2 signal and determining time durations between the peaks or valleys.

4. The method of claim 3 wherein determining the one or more respiration-SPO2 parameters comprises calculating a cycle ratio based on a respiration signal cycle time duration and a mean time duration of SPO2 signal cycles within the synchronized SPO2 signal.

5. The method of claim 3 wherein determining the one or more respiration-SPO2 parameters comprises calculating a timing ratio based on a respiration signal cycle time duration and a mean value of the determined time durations associated with the synchronized SPO2 signal.

6. The method of claim 1 wherein determining the one or more waveform parameters comprises determining an amplitude integration parameter associated with the selected first or second cycle.

7. The method of claim 6 wherein determining the one or more respiration-SPO2 parameters comprises calculating an amplitude integration index based on a first amplitude integration parameter associated with the selected first cycle and a second amplitude integration parameter associated with the selected second cycle.

8. The method of claim 1 wherein determining the one or more waveform parameters comprises determining an energy integration parameter associated with the selected first or second cycle.

9. The method of claim 8 wherein determining the one or more respiration-SPO2 parameters comprises calculating an energy integration index based on a first energy integration parameter associated with the selected first cycle and a second energy integration parameter associated with the selected second cycle.

10. The method of claim 1 wherein determining the heart function comprises characterizing cardiac arrhythmia.

11. The method of claim 10 wherein characterizing the cardiac arrhythmia comprises identifying a severity, type or location of the cardiac arrhythmia.

12. The method of claim 1 further comprising performing a statistical evaluation of the one or more respiration-SPO2 parameters over a plurality of heart cycles.

13. The method of claim 12 wherein performing the statistical evaluation comprises calculating a mean, standard deviation, variation or variability.

14. The method of claim 1 further comprising acquiring the SPO2 signal data by pulse oximetry.

15. The method of claim 1 further comprising acquiring the respiration signal data by using a capnograph.

16. The method of claim 1 further comprising extracting the respiration signal from electrocardiography signal waveforms during respiration.

17. The method of claim 1 further comprising using an artificial neural network to combine the respiration-SPO2 parameters with other types of patient data to generate output parameters that are used to characterize the biological tissue function.

18. A non-transitory computer readable medium embodying a program of instructions executable by machine to perform steps for heart function analysis, the steps comprising:

receiving patient signal data from a patient, the patient signal data including SPO2 signal data received from an oximeter and indicative of saturation of hemoglobin with oxygen and respiration signal data received from a respiratory monitor;

using a signal data analysis unit to synchronize the SPO2 signal data by gating the SPO2 signal using the respiration signal to select a first cycle of the SPO2 signal which corresponds to expiration of the patient and a second cycle of the SPO2 signal which corresponds to inspiration of the patient;

determining one or more waveform parameters based on the selected cycles of the synchronized SPO2 signal data;

determining one or more respiration-SPO2 parameters based on the one or more waveform parameters;

determining a cardiac arrhythmia classification based on the one or more respiration-SPO2 parameters; and

generating a patient report indicating the determined cardiac arrhythmia classification.

19. A system for heart function analysis, comprising:

a patient monitor comprising an oximeter and a respiratory monitor, the patient monitor for receiving patient signal data from a patient, the patient signal data including SPO2 signal data acquired by the oximeter and indicative of saturation of hemoglobin with oxygen and respiration signal data acquired by the respiratory monitor;

a signal data analysis unit for synchronizing the SPO2 signal data by:

gating the SPO2 signal using the respiration signal to select a first cycle of the SPO2 signal which corresponds to expiration of the patient and a second cycle of the SPO2 signal which corresponds to inspiration of the patient;

determining one or more waveform parameters based on the selected cycles of the synchronized SPO2 signal data;

determining one or more respiration-SPO2 parameters based on the one or more waveform parameters;

determining a heart function based on the one or more respiration-SPO2 parameters; and

an output device for presenting a patient report indicating the determined heart function.