Biological tissue function analysis

• US 9,402,571 B2
• Filed: 02/26/2014
• Issued: 08/02/2016
• Est. Priority Date: 01/06/2011
• Status: Active Grant

• Current Assignee: PixArt Imaging Incorporated
• Original Assignee: Siemens Medical Solutions USA Incorporated (Siemens AG)
• Inventors: Zhang, Hongxuan
• Primary Examiner(s): RIVERA VARGAS, MANUEL A
• Application Number:
  US14/190,294
• Publication Number:
  US 20140180037A1
• Time in Patent Office: 888 Days
• US Class Current: 1/1
• CPC Class Codes: A61B 5/021 Measuring pressure in heart or blood vessels A61B5/0205 takes precedence
• CPC Class Codes: A61B 5/02416 using photoplethysmograph signals, e.g. generated by infrared radiation A61B5/14552 takes precedence
• CPC Class Codes: A61B 5/14551 for measuring blood gases
• CPC Class Codes: A61B 5/361 Detecting fibrillation
• CPC Class Codes: A61B 5/363 Detecting tachycardia or bradycardia
• CPC Class Codes: A61B 5/7203 for noise prevention, reduction or removal
• CPC Class Codes: A61B 5/7207 of noise induced by motion artifacts
• CPC Class Codes: A61B 5/7264 Classification of physiological signals or data, e.g. using neural networks, statistical classifiers, expert systems or fuzzy systems neural networks per se G06N3/00; expert systems per se G06N5/00
• CPC Class Codes: A61B 5/7282 Event detection, e.g. detecting unique waveforms indicative of a medical condition A61B5/4094, A61B5/4818, A61B5/349, A61B5/0823 take precedence
• CPC Class Codes: A61B 5/746 Alarms related to a physiological condition, e.g. details of setting alarm thresholds or avoiding false alarms alarms per se G08B
• CPC Class Codes: G16H 50/20 for computer-aided diagnosis, e.g. based on medical expert systems

Abstract

Disclosed herein is a framework for facilitating biological tissue function analysis. In accordance with one aspect, saturation of hemoglobin with oxygen (SPO2) signal data is synchronized with respiration signal data. One or more waveform parameters may be generated based on the synchronized SPO2 signal data and the respiration signal data. One or more respiration-SPO2 parameters may then be determined based on the one or more waveform parameters and used to characterize the biological tissue function.

Claims

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.