Method and system for monitoring hemodynamics

• US 9,380,947 B2
• Filed: 07/25/2012
• Issued: 07/05/2016
• Est. Priority Date: 07/25/2011
• Status: Active Grant

• Current Assignee: Baxter Healthcare SA (Baxter International Inc.), Baxter International Inc.
• Original Assignee: Cheetah Medical, Inc. (Baxter International Inc.)
• Inventors: Marcovitch, Shmuel, Shusman, Eliezer, Rotenberg, David, Levy, Baruch, Avidor, Dan
• Primary Examiner(s): MALAMUD, DEBORAH LESLIE
• Application Number:
  US14/235,101
• Publication Number:
  US 20150366468A1
• Time in Patent Office: 1,441 Days
• US Class Current: 1/1
• CPC Class Codes: A61B 5/02007 Evaluating blood vessel condition, e.g. elasticity, compliance
• CPC Class Codes: A61B 5/02028 Determining haemodynamic parameters not otherwise provided for, e.g. cardiac contractility or left ventricular ejection fraction
• CPC Class Codes: A61B 5/0205 Simultaneously evaluating both cardiovascular conditions and different types of body conditions, e.g. heart and respiratory condition
• CPC Class Codes: A61B 5/024 Detecting, measuring or recording pulse rate or heart rate A61B5/0205, A61B5/021 take precedence
• CPC Class Codes: A61B 5/026 Measuring blood flow A61B3/1233, A61B3/1241 take precedence
• CPC Class Codes: A61B 5/029 Measuring or recording blood output from the heart, e.g. minute volume A61B8/065 takes precedence
• CPC Class Codes: A61B 5/053 Measuring electrical impedance or conductance of a portion of the body
• CPC Class Codes: A61B 5/14535 for measuring haematocrit
• CPC Class Codes: A61B 5/318 Heart-related electrical modalities, e.g. electrocardiography [ECG]
• CPC Class Codes: A61B 5/349 Detecting specific parameters of the electrocardiograph cycle
• CPC Class Codes: A61B 5/412 Detecting or monitoring sepsis
• CPC Class Codes: A61B 5/4818 Sleep apnoea
• CPC Class Codes: A61B 5/4836 Diagnosis combined with treatment in closed-loop systems or methods A61B5/0036 takes precedence
• CPC Class Codes: A61B 5/4875 Hydration status, fluid retention of the body
• CPC Class Codes: A61B 5/7228 Signal modulation applied to the input signal sent to patient or subject; demodulation to recover the physiological signal modulation H03C
• CPC Class Codes: A61B 5/7239 using differentiation including higher order derivatives
• CPC Class Codes: A61B 8/065 to determine blood output from the heart in general A61B5/029

Abstract

A system for monitoring hemodynamics of a subject is disclosed. The system comprises: a signal generating system configured for providing at least an output electric signal and transmitting the output signal to an organ of the subject. The system also comprises a demodulation system configured for receiving an input electrical signal sensed from the organ responsively to the output electric signal, and for modulating the input signal using the output signal to provide an in-phase component and a quadrature component of the input signal. The system also comprises a processing system configured for monitoring the hemodynamics based on the in-phase and the quadrature components.

Claims

1. A system for monitoring hemodynamics of a subject, comprising:

a signal generating system configured for providing at least an output electric signal and transmitting said output signal to an organ of the subject;

a demodulation system configured for receiving an input electrical signal sensed from the organ responsively to said output electric signal, and for modulating said input signal using said output signal to provide an in-phase component and a quadrature component of said input signal;

a processing system configured combine said in-phase component with said quadrature component thereby to generate a hybrid signal, and for monitoring the hemodynamics based at least in part on said hybrid signal wherein said hybrid signal comprises a linear combination of said components.

2. The system according to claim 1, wherein said signal generating system is configured for providing a first output electric signal and a second output electric signal, and transmitting each of said output signals to a separate part of the organ;

and

wherein said demodulation system is configured for receiving an input electrical signal sensed from each part of the organ responsively to a respective output electric signal, and for modulating signals to provide an in-phase component and a quadrature component of each of said input signals.

3. The system according to claim 2, wherein said first and said second output electric signals are dependent electrical signals.

4. The system according to claim 2, wherein said first and said second output electric signals are independent electrical signals.

5. The system according to claim 2, wherein said processing system is configured to combine, for each input signal, a respective in-phase component with a respective quadrature component thereby to generate a hybrid signal corresponding to said input signal, and wherein said monitoring is based at least in part on said hybrid signals.

6. The system according to claim 5, wherein said processing system is configured to combine said hybrid signals, thereby to provide a combined hybrid signal, and wherein said monitoring is based at least in part on said combined hybrid signals.

7. The system according to claim 6, wherein said processing system is configured to asses, based on said combined hybrid signal, at least one property selected from the group consisting of stroke volume (SV), cardiac output (CO), ventricular ejection time (VET), cardiac index (CI), thoracic fluid content (TFC), total peripheral resistance index (TPRI), blood vessel compliance, oxygen uptake efficiency slope (OUES), and a derivative of a phase component of said input signal.

8. The system according to claim 6, wherein said processing system is configured to estimate exercise capacity of the subject based on said combined hybrid signal.

9. The system according to claim 6, wherein said processing system is configured to identify sleep apnea events based on said combined hybrid signal.

10. The system according to claim 6, wherein said processing system is configured to assess the likelihood that the subject develops sepsis based on said combined hybrid signal.

11. The system according to claim 6, wherein said processing system is configured to predict onset of electromechanical dissociation based on said combined hybrid signal.

12. The system according to claim 6, wherein said processing system is configured to assess blood hematocrit based on said combined hybrid signal.

13. The system according to claim 2, wherein said processing system is configured to combine an in-phase component of a first input signal with an in-phase component of a second input signal to provide a combined in-phase signal, and wherein said monitoring is based at least in part on said combined in-phase signal.

14. The system according to claim 2, wherein said processing system is configured to combine a quadrature component of a first input signal with a quadrature component of a second input signal to provide a combined quadrature signal, and wherein said monitoring is based at least in part on said combined quadrature signal.

15. The system according to claim 2, wherein said processing system is configured to calculate, for each input signal, a phase component, an amplitude component, and a phase-amplitude hybrid signal defined as a combination of phase component with amplitude component, and wherein said monitoring is based at least in part on said combination.

16. The system according to claim 15, wherein said processing system is configured to combine a phase-amplitude hybrid signal corresponding to said first input signal with a phase-amplitude hybrid signal corresponding to said second input signal, thereby to provide a combined phase-amplitude hybrid signal and wherein said monitoring is based at least in part on said combined phase-amplitude hybrid signal.

17. The system according to claim 16, wherein said processing system is configured to assess, based on said combined phase-amplitude hybrid signal, at least one property selected from the group consisting of stroke volume (SV), cardiac output (CO), ventricular ejection time (VET), cardiac index (CI), thoracic fluid content (TFC), total peripheral resistance index (TPRI), blood vessel compliance, oxygen uptake efficiency slope (OUES), and a derivative of a phase component of said input signal.

18. A method of monitoring hemodynamics of a subject, comprising:

generating at least an output electric signal and transmitting said output signal to an organ of the subject;

sensing an input electrical signal from the organ responsively to said output electric signal;

modulating said input signal using said output signal to provide an in-phase component and a quadrature component of said input signal;

combining said in-phase component with said quadrature component to generate a hybrid signal; and

monitoring the hemodynamics based at least in part on said hybrid signal;

wherein said hybrid signal comprises a linear combination of said components.

19. The method according to claim 18, wherein said generating and said transmitting comprises providing a first output electric signal and a second output electric signal, and transmitting each of said output signals to a separate part of the organ;

wherein said sensing comprises sensing an input electrical signal from each part of the organ responsively to a respective output electric signal; and

wherein said modulating comprise modulating each input signal to provide an in-phase component and a quadrature component of said input signal.

20. The method according to claim 19, further comprising combining, for each input signal, a respective in-phase component with a respective quadrature component to generate a hybrid signal corresponding to said input signal, wherein said monitoring is based at least in part on said hybrid signals.

21. The method according to claim 20, further comprising combining said hybrid signals to provide a combined hybrid signal, wherein said monitoring is based at least in part on said combined hybrid signals.

22. The method according to claim 19, further comprising combining an in-phase component of a first input signal with an in-phase component of a second input signal to provide a combined in-phase signal, wherein said monitoring is based at least in part on said combined in-phase signal.

23. The method according to claim 19, further comprising combining a quadrature component of a first input signal with a quadrature component of a second input signal to provide a combined quadrature signal, wherein said monitoring is based at least in part on said combined quadrature signal.

24. The method according to claim 19, further comprising calculating, for each input signal, a phase component, an amplitude component, and a phase-amplitude hybrid signal defined as a combination of phase component with amplitude component, wherein said monitoring is based at least in part on said combination.

25. The method according to claim 24, further comprising combining a phase-amplitude hybrid signal corresponding to said first input signal with a phase-amplitude hybrid signal corresponding to said second input signal to provide a combined phase-amplitude hybrid signal, wherein said monitoring is based at least in part on said combined phase-amplitude hybrid signal.

26. A system for monitoring hemodynamics of a subject, comprising:

a signal generating system configured for providing at least an output electric signal and transmitting said output signal to an organ of the subject;

a demodulation system configured for receiving an input electrical signal sensed from the organ responsively to said output electric signal, and for modulating said input signal using said output signal to provide an in-phase component and a quadrature component of said input signal;

a processing system configured combine said in-phase component with said quadrature component thereby to generate a hybrid signal, and for monitoring the hemodynamics based at least in part on said hybrid signal wherein said hybrid signal comprises a non-linear combination of said components.

27. The system according to claim 26, wherein said signal generating system is configured for providing a first output electric signal and a second output electric signal, and transmitting each of said output signals to a separate part of the organ;

and

wherein said demodulation system is configured for receiving an input electrical signal sensed from each part of the organ responsively to a respective output electric signal, and for modulating signals to provide an in-phase component and a quadrature component of each of said input signals.

28. The system according to claim 27, wherein said first and said second output electric signals are dependent electrical signals.

29. The system according to claim 27, wherein said first and said second output electric signals are independent electrical signals.

30. The system according to claim 27, wherein said processing system is configured to combine, for each input signal, a respective in-phase component with a respective quadrature component thereby to generate a hybrid signal corresponding to said input signal, and wherein said monitoring is based at least in part on said hybrid signals.

31. The system according to claim 30, wherein said processing system is configured to combine said hybrid signals, thereby to provide a combined hybrid signal, and wherein said monitoring is based at least in part on said combined hybrid signals.

32. The system according to claim 31, wherein said processing system is configured to perform, based on said combined hybrid signal, at least one operation selected from the group consisting of:

(i) assessing at least one property selected from the group consisting of stroke volume (SV), cardiac output (CO), ventricular ejection time (VET), cardiac index (CI), thoracic fluid content (TFC), total peripheral resistance index (TPRI), blood vessel compliance, oxygen uptake efficiency slope (OUES), and a derivative of a phase component of said input signal;

(ii) estimating exercise capacity of the subject;

(iii) identifying sleep apnea events;

(iv) assessing the likelihood that the subject develops sepsis;

(v) predicting onset of electromechanical dissociation; and

(vi) assessing blood hematocrit.

33. The system according to claim 27, wherein said processing system is configured to combine an in-phase component of a first input signal with an in-phase component of a second input signal to provide a combined in-phase signal, and wherein said monitoring is based at least in part on said combined in-phase signal.

34. The system according to claim 27, wherein said processing system is configured to combine a quadrature component of a first input signal with a quadrature component of a second input signal to provide a combined quadrature signal, and wherein said monitoring is based at least in part on said combined quadrature signal.

35. The system according to claim 27, wherein said processing system is configured to calculate, for each input signal, a phase component, an amplitude component, and a phase-amplitude hybrid signal defined as a combination of phase component with amplitude component, and wherein said monitoring is based at least in part on said combination.

36. The system according to claim 35, wherein said processing system is configured to combine a phase-amplitude hybrid signal corresponding to said first input signal with a phase-amplitude hybrid signal corresponding to said second input signal, thereby to provide a combined phase-amplitude hybrid signal and wherein said monitoring is based at least in part on said combined phase-amplitude hybrid signal.

37. The system according to claim 36, wherein said processing system is configured to assess, based on said combined phase-amplitude hybrid signal, at least one property selected from the group consisting of stroke volume (SV), cardiac output (CO), ventricular ejection time (VET), cardiac index (CI), thoracic fluid content (TFC), total peripheral resistance index (TPRI), blood vessel compliance, oxygen uptake efficiency slope (OUES), and a derivative of a phase component of said input signal.

38. A system for monitoring hemodynamics of a subject, comprising:

a signal generating system configured for providing a first output electric signal and a second output electric signal, and transmitting each of said output signals to a separate part of the organ;

a demodulation system configured for receiving an input electrical signal sensed from each part of the organ responsively to a respective output electric signal, and for modulating signals to provide an in-phase component and a quadrature component of each of said input signals; and

a processing system configured to combine, for each input signal, a respective in-phase component with a respective quadrature component thereby to generate a hybrid signal corresponding to said input signal, and wherein said monitoring is based at least in part on said hybrid signals, to combine said hybrid signals, thereby to provide a combined hybrid signal, to monitor the hemodynamics based at least in part on said combined hybrid signals, and to identify sleep apnea events based on said combined hybrid signal.

39. The system according to claim 38, wherein said first and said second output electric signals are dependent electrical signals.

40. The system according to claim 38, wherein said first and said second output electric signals are independent electrical signals.

41. The system according to claim 38, wherein said processing system is configured to asses, based on said combined hybrid signal, at least one property selected from the group consisting of stroke volume (SV), cardiac output (CO), ventricular ejection time (VET), cardiac index (CI), thoracic fluid content (TFC), total peripheral resistance index (TPRI), blood vessel compliance, oxygen uptake efficiency slope (OUES), and a derivative of a phase component of said input signal.

42. The system according to claim 38, wherein said processing system is configured to estimate exercise capacity of the subject based on said combined hybrid signal.

43. The system according to claim 38, wherein said processing system is configured to assess the likelihood that the subject develops sepsis based on said combined hybrid signal.

44. The system according to claim 38, wherein said processing system is configured to predict onset of electromechanical dissociation based on said combined hybrid signal.

45. The system according to claim 38, wherein said processing system is configured to assess blood hematocrit based on said combined hybrid signal.

46. A method of monitoring hemodynamics of a subject, comprising:

generating at least an output electric signal and transmitting said output signal to an organ of the subject;

sensing an input electrical signal from the organ responsively to said output electric signal;

modulating said input signal using said output signal to provide an in-phase component and a quadrature component of said input signal;

combining said in-phase component with said quadrature component to generate a hybrid signal; and

monitoring the hemodynamics based at least in part on said hybrid signal;

wherein said hybrid signal comprises a non-linear combination of said components.

47. The method according to claim 46, wherein said generating and said transmitting comprises providing a first output electric signal and a second output electric signal, and transmitting each of said output signals to a separate part of the organ;

wherein said sensing comprises sensing an input electrical signal from each part of the organ responsively to a respective output electric signal; and

wherein said modulating comprise modulating each input signal to provide an in-phase component and a quadrature component of said input signal.

48. The method according to claim 47, further comprising combining, for each input signal, a respective in-phase component with a respective quadrature component to generate a hybrid signal corresponding to said input signal, wherein said monitoring is based at least in part on said hybrid signals.

49. The method according to claim 48, further comprising combining said hybrid signals to provide a combined hybrid signal, wherein said monitoring is based at least in part on said combined hybrid signals.

50. The method according to claim 47, further comprising combining an in-phase component of a first input signal with an in-phase component of a second input signal to provide a combined in-phase signal, wherein said monitoring is based at least in part on said combined in-phase signal.

51. The method according to claim 47, further comprising combining a quadrature component of a first input signal with a quadrature component of a second input signal to provide a combined quadrature signal, wherein said monitoring is based at least in part on said combined quadrature signal.

52. The method according to claim 47, further comprising calculating, for each input signal, a phase component, an amplitude component, and a phase-amplitude hybrid signal defined as a combination of phase component with amplitude component, wherein said monitoring is based at least in part on said combination.

53. The method according to claim 52, further comprising combining a phase-amplitude hybrid signal corresponding to said first input signal with a phase-amplitude hybrid signal corresponding to said second input signal to provide a combined phase-amplitude hybrid signal, wherein said monitoring is based at least in part on said combined phase-amplitude hybrid signal.