Blood pressure measurement apparatus and method

• US 20030176795A1
• Filed: 12/02/2002
• Published: 09/18/2003
• Est. Priority Date: 06/02/2000
• Status: Abandoned Application

• Current Assignee: Cardionetics Limited
• Original Assignee: Cardionetics Limited
• Inventors: Harris, Thomas John, Needham, Philip
• Application Number:
  US10/307,804
• Publication Number:
  US 20030176795A1
• Time in Patent Office: Days
• US Class Current: 600/485
• CPC Class Codes: A61B 5/02208 using the Korotkoff method
• CPC Class Codes: A61B 5/0225 the pressure being controlled by electric signals, e.g. derived from Korotkoff sounds
• CPC Class Codes: A61B 5/349 Detecting specific parameters of the electrocardiograph cycle
• CPC Class Codes: A61B 5/361 Detecting fibrillation
• CPC Class Codes: A61B 5/363 Detecting tachycardia or bradycardia
• CPC Class Codes: A61B 5/364 Detecting abnormal ECG interval, e.g. extrasystoles, ectopic heartbeats
• CPC Class Codes: A61B 5/366 Detecting abnormal QRS complex, e.g. widening
• CPC Class Codes: A61B 5/7203 for noise prevention, reduction or removal
• CPC Class Codes: A61B 5/7221 Determining signal validity, reliability or quality A61B5/7207 and A61B5/7217 take precedence
• 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 5/7285 for synchronising or triggering a physiological measurement or image acquisition with a physiological event or waveform, e.g. an ECG signal A61B6/5205, A61B6/541, A61B8/5207, A61B8/543 take precedence
• CPC Class Codes: G16H 50/20 for computer-aided diagnosis, e.g. based on medical expert systems

Abstract

A blood pressure measurement apparatus and method is disclosed in which the taking of blood pressure measurements of a patient is controlled in dependence upon the analysis of a signal from the patient indicative of cardiac contractions.

Claims

1. Blood pressure measurement apparatus for measuring the blood pressure of a patient, the apparatus comprising:

receiving means for receiving a signal from the patient indicative of contractions of the heart of the patient;

analysing means for analysing the received signal;

blood pressure measuring means for measuring the blood pressure of the patient;

determining means for determining whether to take a blood pressure measurement on the basis of the analysis of the received signal by ad analysing means; and

control means for controlling the blood pressure measuring means to perform a blood pressure measurement if a blood pressure measurement request signal has been received by said control means and in dependence upon the detention by said determining means.

2. Blood pressure measurement apparats according to claim 1 including generating means for generating said blood pressure measurement signal.

3. Blood pressure measurement apparatus according to claim 2, wherein said generating means is adapted to automatically periodically generate said request signal.

4. Blood pressure measurement apparatus according to claim 2 or claim 3, wherein said generating means is manually operable.

8. Blood pressure measurement apparatus according to any preceding claim wherein said analysing means is adapted to continue to analyse the received signal during a blood pressure measurement, and said deter means is further adapted to determine whether a blood pressure measurement should continue or be aborted on the basis of the analysis of said received signal by said analysing means.

9. Blood pressure measurement apparatus according to claim 8, wherein said analysing means is adapted to identify whether functioning of the heart is suitable for continuance of a blood pressure measurement, and said determining means is adapted to determine to continue to take a blood pressure measurement only if said analysing means has identified the functioning of the heart to be suitable.

10. Blood pressure measurement apparatus according to claim 9, wherein said analysing means is adapted to identify cardiac conditions and/or cardiac rhythms and to classify said cardiac conditions and/or cardiac rhythm as suitable or unstable for a blood pressure measurement.

11. Blood pressure measurement apparatus according to any one of claims 8 to 10, wherein said determining means is further adapted to determine whether to suspend a blood pressure measurement for a number of cardiac cycles on the basis of the analysis of said received signal by said analysing means.

13. Blood pressure measurement apparatus according to any preceding claim, wherein said analysing means is adapted to continuously analysed the received signal.

14. Blood pressure measurement apparatus according to any one of claims 1 to 11, wherein said analysing means is adapted to only perform the analysis of the received signal after said request signal has been received by said control means and whilst the blood pressure measurement is being taken.

15. Blood pre measurement apparatus according to any preceding claim wherein said receiving means is adapted to eve an electro-physiological cardiac signal.

16. Blood pressure measurement apparatus according to any preceding claim wherein said analysing means is adapted to analyse the received signal to determine pulse rate and pulse intervals.

18. Blood pressure measurement apparatus according to any preceding claim, including storage means for sting blood pressure measurements.

19. Blood pressure meant apparatus according to any preceding claim, including signal storage means for storing the received signal.

20. Blood pressure measurement apparatus according to claim 19, wherein said signal storage means is adapted to only store the received signals associated with blood pressure measurements.

21. Blood pressure measurement apparatus according to any preceding claim, including means for storing the result of tie analysis of the received signal.

23. Blood pressure measurement apparatus according to any preceding claim, wherein said analysing means is adapted to extract features from the received signal giving morphological and rhythm information.

24. Blood pressure measurement apparatus according to any preceding claim wherein said blood pressure measuring means comprises oscillometric blood pressure measuring means.

25. Blood pure measurement apparatus according to any one of claim 1 to 23, wherein said blood pressure measuring means comprises auscultatory blood pressure measuring means.

26. Blood pressure measurement apparatus according to claim 25, wherein said blood pressure measuring means is adapted to make R wave Sued measures of blood pressure using the the received signal.

27. Blood pressure measurement apparatus according to any preceding claim, wherein said apparatus is portable and said blood pressure measuring means is an ambulatory blood pressure measuring means.

5. Blood pressure measurement apparatus according to any preceding clam wherein said analysing means is adapted to identify whether it is a suitable time for a blood pressure measurement to be taken and said determining means is adapted to determine to take a blood pressure measurement only if said analysing means has identified the time to be suitable.

6. Blood pressure measurement apparatus according to claim 5, wherein said analysing means is adapted to identify cardiac conditions and/or cardiac rhythms and to classify said cardiac conditions and/or cardiac rhythms as suitable or unsuitable for a blood pressure measurement.

7. Blood pressure measurement apparatus according to claim 6, wherein said analysing means includes neural network means comprising a neural network for each of a plurality of cardiac classifications to clad the received signal based on its morphology, means for determining cardiac rhythm information from said received signal, and means for identifying cardiac conditions and/or cardiac rhythms using the cardiac classifications and the cardiac rhythm information.

12. Blood pressure measurement apparatus according to any prig claim wherein said analysing means is further adapted to analyse the received signal to identify predetermined cardiac events for which a blood pressure measurement is desired, and said determining means is adapted to determine that-a blood pressure measurement is to be taken when said analysing mean identifies a said predetermined cardiac event.

17. Blood pressure measurement apparats according to any preceding wherein said receiving means is adapted to re an ECG signal from the patient.

22. Blood pressure measurement apparatus according to any preceding clam when said analysing means comprises neural network means.

28. A method of measuring the blood pressure of a patient;

the method Comprising;

receiving a signal from the patient indicative of the contractions of the heart of the patient;

analysing the received signal;

generating a blood pressure request signal;

determining whether to take a blood pressure measurement on the basis of the analysis of the received signal; and

taking a blood pressure measurement if said blood pressure measurement request signal has been generated in dependence upon the result of the determination.

29. A method according to claim 28, wherein the request signal is automatically periodically generated.

30. A method according to claim 28 or claim 29, wherein the request signal is manually generated.

34. A method according to any one of claims 28 to 33, wherein the analysing step includes continuing to analyse the received signal during a blood press measurement and a determination step includes determining whether a blood pressure measurement should continue or be aborted on the basis of the analysis of the received signal.

35. A method according to claim 34, wherein the analysing step includes identifying whether the functioning of the heart is stable for continuance of a blood pressure measurement and a determining step includes determining to continue to take blood pressure measurement only if the analysing step has identified the functioning of the heart to be suitable.

36. A method according to claim 35, wherein the analysing step includes identifying cardiac conditions and/or cardiac rhythms and classifying the cardiac conditions and/or cardiac rhythms as suitable or unsuitable for a blood pressure measurement.

37. A method according to any one of claims 34 to 36, wherein the determining step further includes determining whether to suspend a blood pressure measurement for a number of cardiac cycles on the basis of the analysis of the received signal.

38. A method according to any one of claims 28 to 37, including analysing the received signal to identify predetermined cardiac events for which a blood pressure measurement is desired, and taking a blood pressure measure when a said predetermined cardiac event is identified.

39. A method according to any one of claims 37 to 38, wherein the analysing step comprises continuously analysing the received signal.

40. A method according to any one of claim 28 to 37, wherein the analysing step comprises analysing the received signal only after said request signal is generated and whilst the blood pressure measurement is being taken.

41. A method according to any one of claims 28 to 40, including storing blood pressure measurements taken.

42. A method according to any one of claims 28 to 41, including storing the received signal.

43. A method according to claim 42, wherein only the received signal associated with a blood measurement is stared.

44. A method according to any one of claims 28 to 43, including storing a result of the analysis of the received signal.

46. A method according to any one of claims 28 to 45, wherein the analysing step includes extracting features from a received signal which give morphological and rhythm information.

47. A method according to any one of claims 28 to 46, ten The blood pressure measurement is to using oscillometric blood pressure means.

48. A method according to any one of claims 28 to 46, wherein the blood pressure is taken using auscultatory blood pressure measuring means.

49. A method according to claim 48, wherein the blood pressure is taken by making R wave gated measures of blood pressure using the received signal.

50. A method according to any one of claims 28 to 49, wherein the analysing step and the determining step are carried out in a portable apparatus and the blood pressure is taken using an ambulatory blood pressure measuring means.

51. A method according to any one of claims 28 to 50 wherein an electophysiological cardiac signal is received and analysed.

52. A method according to any one of claims 28 to 51 wherein the received signal is analysed to determine pulse rate and pulse intervals.

53. A method according to any one of claims 28 to 52 wherein the received signal is an ECG signal.

31. A method according to any one of clams 28 to 30, wherein the analysis step identifies whether it is a suitable time for a blood pressure measurement to be taken, and a determination step determines that a blood pressure measurement is to be taken only if the analysing step has identified the time to be suitable.

32. A method according to claim 31, wherein the analysing step includes identifying cardiac conditions and/or cardiac rhythms and classify the cardiac conditions and/or cardiac rhythms as suitable or unstable for a blood pressure measurement.

33. A method according to claim 32, wherein the analysing step includes using a neural network for each of a plurality of cardiac classifications to classify the received signal based on its morphology, determining cardiac rhythm information from the received signal, and identifying cardiac conditions and/or cardiac rhythms using the cardiac classifications and the cardiac rhythm information.

45. A method according to any one of clam 28 to 44, wherein the analysing step uses neural network means.