Apparatus and method for precision vital signs determination

• US 20040064054A1
• Filed: 09/30/2002
• Published: 04/01/2004
• Est. Priority Date: 09/30/2002
• Status: Active Grant

• Current Assignee: Michael Macaluso
• Original Assignee: Michael Macaluso
• Inventors: Clift, Vaughan L.
• Granted Patent: US 6,976,963 B2
• Time in Patent Office: Days
• US Class Current: 600/483
• 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 5/021 Measuring pressure in heart or blood vessels A61B5/0205 takes precedence
• CPC Class Codes: A61B 5/02125 of pulse wave propagation time
• 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 5/0809 by impedance pneumography
• CPC Class Codes: A61B 5/0836 Measuring rate of CO2 production
• CPC Class Codes: A61B 5/1455 using optical sensors, e.g. spectral photometrical oximeters

Abstract

Apparatus and techniques are provided for precise measuring and monitoring of certain vital signs of patients that have been difficult to measure especially in emergency situations. Sensor may be used for detecting contraction and expansion in the vascular bed of the lining tissue of the external auditory canal during a cardiac cycle to obtain a better indication of certain physiological parameters. Such a signal generally may be superimposed with an additional signal that is primarily due to breathing activity of the patient. Based on various scenarios different sensors may be used to determine the signal due to breathing activity and thus the physiological parameter of interest may be derived. The signal corresponding to the physiological parameter of interest, for example, blood pressure may then be used to monitor the vital signs or control other medical equipment.

Claims

1. A method comprising:

a. sensing a first signal corresponding to at least one physiological parameter superimposed with at least one undesired signal component by detecting contraction and expansion in the vascular bed of the lining tissue of the external auditory canal during a cardiac cycle;

b. sensing a second signal corresponding to the at least one undesired signal component; and

c. combining the first signal and the second signal to derive a third signal corresponding to the at least one physiological parameter.

2. The method as in claim 1, wherein the at least one physiological parameter comprises a blood pressure.

3. The method as in claim 2, wherein the blood pressure comprises a diastolic blood pressure and a systolic blood pressure.

4. The method as in claim 1, wherein the at least one physiological parameter comprises a pulse rate.

5. The method as in claim 1, wherein the at least one physiological parameter comprises a pulse pressure.

6. The method as in claim 1, wherein the sensing the first signal comprises acquiring a first electrical signal generated by a first sensor in response to contraction and expansion in the vascular bed of the lining tissue of the external auditory canal during a cardiac cycle.

7. The method as in claim 1, wherein the sensing the second signal comprises acquiring a second electrical signal generated by a second sensor in response to the respiratory activity during the cardiac cycle.

8. A method comprising:

a. sensing a first signal corresponding to a blood pressure superimposed with a signal component corresponding to a respiratory cycle by detecting contraction and expansion in the vascular bed of the lining tissue of the external auditory canal during a cardiac cycle;

b. sensing a second signal representing the signal component corresponding to the respiratory cycle; and

c. removing the second signal from the first signal to derive a third signal corresponding to the blood pressure.

9. The method as in claim 8, wherein the blood pressure comprises of a diastolic blood pressure and a systolic blood pressure.

10. The method as in claim 9, further comprising of determining a blood pressure paradox.

11. The method as in claim 10, wherein the blood pressure paradox comprises a time variation of the systolic blood pressure with changes in a respiratory cycle.

12. The method as in claim 10, wherein the changes in the respiratory cycle comprise changes during breathing in and changes during breathing out.

13. The method as in claim 10, wherein the blood pressure paradox is used as an indicator of a disease state.

14. An apparatus for determining at least one physiological parameter, the apparatus comprising:

a. a first sensor for sensing a first signal corresponding to contraction and expansion in the vascular bed of the lining tissue of the external auditory canal during a cardiac cycle;

b. a second sensor for sensing a second signal representing effect on the at least one physiological parameter due to respiratory cycle; and

c. a processor coupled to the first sensor and the second sensor to combine the first signal and the second signal to generate a third signal corresponding to the at least one physiological parameter.

15. The apparatus as in claim 14, wherein the determining the at least one physiological parameter further includes monitoring the at least one physiological parameter.

16. The apparatus as in claim 14, wherein the first sensor comprises a pressure sensor for sensing pressure variations corresponding to contraction and expansion in the vascular bed of the lining tissue of the external auditory canal during a cardiac cycle.

17. The apparatus as in claim 16, wherein the blood pressure comprises a diastolic blood pressure and a systolic blood pressure.

18. The apparatus as in claim 14, wherein the at least one physiological parameter comprises a pulse rate.

19. The apparatus as in claim 14, wherein the at least one physiological parameter comprises a pulse pressure.

20. The apparatus as in claim 14, wherein the response to the second signal is obtained using nasal airflow.