Method and apparatus for continuous non-invasive monitoring of blood pressure parameters

• US 6,004,274 A
• Filed: 02/26/1998
• Issued: 12/21/1999
• Est. Priority Date: 09/11/1995
• Status: Expired due to Term

• Current Assignee: Moody, Trevor J., Nolan, James A.
• Original Assignee: Moody, Trevor J., Nolan, James A.
• Inventors: Moody, Trevor J., Nolan, James A.
• Primary Examiner(s): O'Connor, Cary
• Assistant Examiner(s): ASTORINO, MICHAEL C
• Application Number:
  US09/031,358
• Time in Patent Office: 663 Days
• Field of Search: 600/485, 600/486, 600/481, 600/479, D24/106, 607/136, 128/857
• US Class Current: 600/486
• CPC Class Codes: A61B 1/2275 with controlled air pressure
• CPC Class Codes: A61B 2560/0223 of calibration, e.g. protocols for calibrating sensors
• CPC Class Codes: A61B 5/0002 Remote monitoring of patients using telemetry, e.g. transmission of vital signals via a communication network A61B5/07 takes precedence; transmission systems for measured values G08C; transmission H04B; transmission of digital information H04L; wireless communication networks H04W
• CPC Class Codes: A61B 5/021 Measuring pressure in heart or blood vessels A61B5/0205 takes precedence
• CPC Class Codes: A61B 5/02108 from analysis of pulse wave characteristics
• CPC Class Codes: A61B 5/6817 Ear canal

Abstract

Continuous, non-invasive method and apparatus for measuring blood pressure parameters and the like are disclosed. One disclosed apparatus includes an earpiece for sealing an individual'"'"'s ear canal so that arterial blood pressure changes adjacent the sealed ear canal produce air pressure changes in the sealed ear canal. The apparatus further includes pressure sensing means for measuring the air pressure changes in the sealed ear canal and producing a signal related to the measured air pressure changes. In addition, the apparatus preferably includes processing means for processing the signal to measure blood pressure parameters, as well as means for displaying and/or recording the processed signal. The method may be used to determine heart rate, blood pressure, cardiac output, stroke volume, cardiac function, circulatory function, and other parameters. To obtain absolute pressure readings, two sensors, one in each ear, may be used to monitor pulse time transit delay.

Claims

1. An apparatus for measuring blood pressure parameters comprising:

an earpiece; and

measuring means cooperating with said earpiece for measuring arterial blood pressure changes adjacent the ear canal.

2. An apparatus as claimed in claim 1 wherein said measuring means includes sensing means for measuring movement in the wall of an individual'"'"'s ear canal which is caused by arterial blood pressure changes adjacent the ear canal.

3. An apparatus as claimed in claim 2 wherein said sensing means includes a strain gauge and wherein said strain gauge is built into said earpiece so as to be capable of measuring movement transmitted through said earpiece from the wall of the individual'"'"'s ear canal.

4. An apparatus as claimed in claim 1 wherein said earpiece includes means for sealing an individuals ear canal so that arterial blood pressure changes adjacent the sealed ear canal produce air pressure changes in the sealed ear canal;

and wherein said measuring means includes pressure sensing means for measuring the air pressure changes in the sealed ear canal.

5. An apparatus as claimed in claim 4 wherein said pressure sensing means is mounted in said earpiece.

6. An apparatus as claimed in claim 4 further comprising:

means for adjusting the air pressure within the sealed ear canal.

7. An apparatus as claimed in claim 4 wherein said pressure sensing means produces a signal which is directly related to the measured air pressure changes.

8. An apparatus as claimed in claim 7 wherein the signal is an electrical signal.

9. An apparatus as claimed in claim 8 wherein the pressure sensing means is a member selected from the group consisting of piezoelectric transducers, strain gauges and ceramic transducers.

10. An apparatus as claimed in claim 7 wherein the signal is a mechanical signal.

11. An apparatus as claimed in claim 7 wherein the signal is a volumetric displacement.

12. An apparatus as claimed in claim 7 further comprising:

means in communication with said pressure sensing means for displaying the signal produced by said pressure sensing means.

13. An apparatus as claimed in claim 7 further comprising:

means in communication with said pressure sensing means for recording the signal produced by said pressure sensing means.

14. An apparatus as claimed in claim 7 further comprising:

means for calibrating the signal with a reading produced by an independent blood pressure measuring means.

15. An apparatus as claimed in claim 7 further comprising:

means in communication with said pressure sensing means for processing the signal produced by said pressure sensing means to monitor blood pressure parameters.

16. An apparatus as claimed in claim 15 wherein said processing means includes means for generating an audio signal which is directed to the sealed ear canal.

17. An apparatus as claimed in claim 16 wherein said means generates an audio signal when a predetermined blood pressure is detected.

18. An apparatus as claimed in claim 16 wherein all components thereof are built into said apparatus so that said apparatus is capable of being worn by an individual when said earpiece thereof is inserted into the individual'"'"'s ear canal.

19. An apparatus as claimed in claim 18 further comprising housing means for containing battery means and said processing means.

20. An apparatus as claimed in claim 15 wherein the blood pressure parameters are selected from the group consisting of heart rate, systolic pressure, diastolic pressure, mean arterial pressure, continuous blood pressure waveform, stroke volume, cardiac output, respiration rate and respiration volume.

21. An apparatus as claimed in claim 15 further comprising:

means for displaying the processed signal.

22. An apparatus as claimed in claim 15 further comprising:

means for recording the processed signal.

23. An apparatus as claimed in claim 15 further comprising:

transmitting means in communication with said pressure sensing means for transmitting the signal produced by said pressure sensing means to said processing means.

24. An apparatus as claimed in claim 23 wherein said transmitting means hard wired.

25. An apparatus as claimed in claim 23 wherein said transmitting means is wireless.

26. An apparatus as claimed in claim 25 wherein said wireless transmitting means includes a member selected from the group consisting of radio transmission means, ultrasonic transmission means, and photonic transmission means.

27. A system for measuring blood pressure comprising:

an earpiece for sealing an individual'"'"'s ear canal;

pressure sensing means mounted in said earpiece for measuring air pressure changes in the ear canal when the ear canal is sealed with said earpiece wherein the air pressure changes are related to arterial blood pressure changes adjacent the ear canal, said pressure sensing means also producing a signal which is directly related to the measured air pressure changes;

auxiliary blood pressure measuring means for independently measuring a parameter of the individual'"'"'s blood pressure, the measurement of which is used to calibrate the signal produced by said pressure sensing means;

processing means for processing the signal to measure blood pressure parameters; and

transmitting means in communication with said pressure sensing means for transmitting the signal produced by said pressure sensing means to said processing means.

28. A system as claimed in claim 27 further comprising:

means for displaying the processed signal.

29. A system for measuring blood pressure parameters comprising:

earpiece means for sealing both ear canals of an individual so that arterial blood pressure changes adjacent each sealed ear canal produce air pressure changes in each sealed ear canal;

pressure sensing means for measuring the air pressure changes in each sealed ear canal and producing a signal for each sealed ear canal which is related to the measured air pressure changes; and

processing means for processing and comparing the signals of each sealed ear canal to measure a blood pressure related parameter of the individual.

30. A system as claimed in claim 29 further comprising:

transmitting means in communication with said pressure sensing means for transmitting the signals produced by said pressure sensing means to said processing means.

31. A system as claimed in claim 29 wherein said processing means includes means for measuring the time delay between the signals.

32. A method of measuring blood pressure parameters comprising:

sealing an individual'"'"'s ear canal so that arterial blood pressure changes adjacent the sealed ear canal produce air pressure changes in the sealed ear canal; and

measuring the air pressure changes in the sealed ear canal.

33. A method as claimed in claim 32 further comprising:

producing a signal which is directly related to the measured air pressure changes.

34. A method as claimed in claim 33 further comprising:

displaying the signal.

35. A method as claimed in claim 33 further comprising:

recording the signal.

36. A method as claimed in claim 33 further comprising:

processing the signal to monitor a blood pressure parameter.

37. A method as claimed in claim 33 further comprising:

calibrating the signal with a reading produced by an independent blood pressure measuring means.

38. A method of measuring a blood pressure parameter comprising:

sealing both ear canals of an individual so that arterial blood pressure changes adjacent each sealed ear canal produce air pressure changes in each sealed ear canal;

measuring the air pressure changes in each sealed ear canal;

producing a signal for each sealed ear canal which is related to the measured air pressure changes; and

comparing the signals of each sealed ear canal to measure a blood pressure related parameter of the individual.

39. A method as claimed in claim 38 wherein said step of comparing includes measuring the time delay between the signals.

40. A method of measuring blood pressure parameters comprising:

wearing an earpiece including means for measuring arterial blood pressure changes adjacent the ear canal; and

measuring arterial blood pressure changes adjacent the ear canal with said earpiece.