NON-INVASIVELY MEASURING PHYSIOLOGICAL PROCESS

• US 20120108989A1
• Filed: 07/05/2010
• Published: 05/03/2012
• Est. Priority Date: 07/06/2009
• Status: Active Grant

• Current Assignee: Heard Systems Pty Ltd.
• Original Assignee: Heard Systems Pty Ltd.
• Inventors: Gargiulo, Gaetano, Tapson, Jonathan Craig, Shephard, Richard William
• Granted Patent: US 8,652,063 B2
• Time in Patent Office: Days
• US Class Current: 600/508
• CPC Class Codes: A61B 2503/40 Animals
• CPC Class Codes: A61B 2562/0219 Inertial sensors, e.g. accelerometers, gyroscopes, tilt switches
• CPC Class Codes: A61B 5/02411 of foetuses
• CPC Class Codes: A61B 5/344 Foetal cardiography
• CPC Class Codes: A61B 5/4343 Pregnancy and labour monitoring, e.g. for labour onset detection
• CPC Class Codes: A61B 5/4362 Assessing foetal parameters
• CPC Class Codes: A61B 7/00 Instruments for auscultation

Abstract

Equipment (10) for non-invasively measuring a physiological process includes at least one receiver (12) to be placed relative to a body of a subject being examined to detect at least one signal from the body of the subject. A discrimination unit (20.1) determines if the at least one signal is a signal of interest associated with the physiological process. A processor (20) processes the signal of interest to enhance the signal of interest and suppresses other received signals that are not of interest.

Claims

1. A method of non-invasively measuring a physiological process, the method including:

placing at least one receiver relative to a body of a subject being examined and using the at least one receiver to detect at least one signal from the body of the subject;

determining if the at least one signal is a signal of interest associated with the physiological process; and

pre-processing the signal of interest to enhance the signal of interest and to suppress other received signals that are not of interest.

2. The method of claim 1 in which the physiological process to be measured is the presence of a foetal cardiac signal and in which the method includes determining the presence of foetal cardiac signals within naturally radiated signals obtained from the placement of one or more receivers against or near the body of the subject being examined.

3. The method of claim 2 which includes detecting the presence of one or more cardiac signals by determining if periodic repetitions at a rate consistent with a foetal heart rate occurs.

4. The method of claim 3 which includes, once the presence of one or more cardiac signals has been detected, determining if a foetal cardiac signal is present.

5. The method of claim 4 which includes determining from the receiver data that there is more than one cardiac signal present and, if more than one cardiac signal at different rates is found in the receiver data, confirming pregnancy of the subject.

6. The method of claim 3 which includes, if only one cardiac signal is detected, determining if the detected signal is maternal or foetal.

7. The method of claim 6 which includes measuring the maternal heart rate separately.

8. The method of claim 7 which includes measuring the maternal heart rate by at least one of (a) applying the at least one receiver to a region where the maternal cardiac signal is known to be strong and foetal cardiac signals are known to be absent or weak and (b) measuring the maternal heart rate by means other than the use of the at least one receiver.

9. The method of claim 3 which includes processing the received signals to determine signal quality.

10. The method of claim 9 which includes monitoring and evaluating variations in signal quality in real time and feeding data relating to the signal quality back to an operator.

11. The method of claim 10 which includes, once the data have been obtained, automating a task of diagnosing the presence of a foetal cardiac signal using at least one predetermined technique.

12. The method of claim 11 which includes using a number of the techniques in parallel.

13. The method of claim 11 which includes effecting pre-processing enhancement of interest prior to applying the at least one technique.

15. The method of claim 12 which includes combining outputs of the applied techniques, using a classifier, to make a final decision.

16. The method of claim 15 which includes further outputting, as part of the decision, data relating to a measure of confidence in the decision.

17. The method of claim 3 which includes combining historical data with data obtained from the a least one receiver to produce an updated estimate of pregnancy status, number of foetuses, foetal age and predicted time until parturition for a number of subjects being investigated.

18. The method of claim 3 which includes transferring multi-field data in a format suitable for inclusion with computer software.

14. The method of 13 which includes effecting pre-processing enhancement of the signal by using a combination of low-pass, band-pass, and high-pass filtering.

19. Equipment for non-invasively measuring a physiological process, the equipment including:

at least one receiver to be placed relative to a body of a subject being examined to detect at least one signal from the body of the subject;

a discrimination unit for determining if the at least one signal is a signal of interest associated with the physiological process; and

a processor for processing the signal of interest to enhance the signal of interest and to suppress other received signals that are not of interest.

20. The equipment of claim 19 which includes a receiver pack comprising a plurality of receivers operable to detect different types of signals.

21. The equipment of claim 20 in which the receiver pack includes at least some of the following types of receivers:

at least one audio receiver for receiving sound wave information from the subject being examined;

at least one electrical receiver for receiving muscle and nerve electrical activity signals from the subject being examined; and

at least one pressure receiver for receiving kinetic information from the subject being examined.

22. The equipment of claim 20 in which the processor is in communication with the receiver pack for processing the received signals, performing computations to enhance the signal of interest and to filter noise and other signals not of interest to provide refined signals.

23. The equipment of claim 22 in which the processor employs algorithms to interpret the refined signals and provide an output in the form of information on the physiological process.

24. The equipment of claim 19 in which the discrimination unit comprises a pre-processing module for effecting pre-processing of the signal of interest.

25. The equipment of claim 24 in which the pre-processing module uses a combination of low-pass, band-pass and high-pass filtering.

26. The equipment of claim 19 in which the processor includes an evaluation module for monitoring and evaluating variations in signal quality in real time.

27. The equipment of claim 26 which includes an enunciator for alerting an operator to the signal quality.

28. The equipment of claim 19 in which the processor is configured to automate a task of diagnosing the presence of a foetal cardiac signal using at least one predetermined technique.

29. The equipment of claim 28 in which the processor is configured to use a number of the techniques in parallel.

30. The equipment of claim 29 in which the processor includes a classifier which is operable to combine outputs of the applied techniques to make a final decision about the signal of interest.

31. The equipment of claim 30 in which the processor is configured to output, as part of the decision, data relating to a measure of confidence in the decision.

32. The equipment of claim 19 which includes a data storage system for recording and accessing data from multiple animals and events.

33. The equipment of claim 19 which includes a portable power supply.

34. The equipment of claim 19 which includes a data input and processing system for combining historical and current data.

35. The equipment of claim 19 which includes an output system for transferring multi-field data in a format suitable for inclusion with computer software.