Blood flow volume measurement method and vital sign monitoring apparatus

• US 6,652,466 B2
• Filed: 02/28/2002
• Issued: 11/25/2003
• Est. Priority Date: 03/01/2001
• Status: Active Grant

• Current Assignee: Nihon Kohden Corporation
• Original Assignee: Nihon Kohden Corporation
• Inventors: Ozawa, Hideo, Sugo, Yoshihiro, Hyogo, Mitsushi
• Primary Examiner(s): Hindenburg, Max F.
• Assistant Examiner(s): Natnithithadha, Navin
• Application Number:
  US10/084,309
• Publication Number:
  US 20020151805A1
• Time in Patent Office: 635 Days
• Field of Search: 600/481, 600/483, 600/485, 600/504, 600/505, 600/506, 600/507, 600/486, 600/490, 600/492, 600/493, 600/494, 600/495
• US Class Current: 600/504
• CPC Class Codes: A61B 5/02125 of pulse wave propagation time
• CPC Class Codes: A61B 5/022 by applying pressure to close blood vessels, e.g. against the skin; Ophthalmodynamometers
• CPC Class Codes: A61B 5/026 Measuring blood flow A61B3/1233, A61B3/1241 take precedence
• CPC Class Codes: A61B 5/0285 Measuring or recording phase velocity of blood waves

Abstract

A vital sign monitoring apparatus has estimated blood pressure calculation device for calculating estimated systolic blood pressure and estimated diastolic blood pressure from information relevant to blood pressure successively measured based on the relationship between information relevant to blood pressure and systolic blood pressure and the relationship between information relevant to blood pressure and diastolic blood pressure, systolic and diastolic duration measurement device for successively measuring a systolic duration and a diastolic duration, and blood flow volume calculation device for calculating a blood flow volume based on the estimated systolic blood pressure and the estimated diastolic blood pressure successively calculated and the systolic duration and the diastolic duration successively measured.

Claims

1. A blood flow volume measurement method of measuring a blood flow volume ejected by cardiac contraction in a vital sign monitoring apparatus, said blood flow volume measurement method comprising the steps of:

calculating estimated systolic blood pressure and estimated diastolic blood pressure from information relevant to blood pressure measured based on the relationship between information relevant to blood pressure and systolic blood pressure and the relationship between information relevant to blood pressure and diastolic blood pressure;

measuring a systolic duration and a diastolic duration; and

calculating a blood flow volume ejected by cardiac contraction based on the estimated systolic blood pressure and the estimated diastolic blood pressure calculated and the systolic duration and the diastolic duration measured.

2. The blood flow volume measurement method as claimed in claim 1, wherein said step of calculating the blood flow volume calculates the cardiac output per unit time using a heart rate or a pulse rate measured.

3. The blood flow volume measurement method as claimed in claim 1, wherein the relationship between information relevant to blood pressure and systolic blood pressure and the relationship between information relevant to blood pressure and diastolic blood pressure are determined by the information relevant to blood pressure measured at blood pressure measuring time with a cuff and the systolic blood pressure and the diastolic blood pressure measured by blood pressure measurement with the cuff.

4. The blood flow volume measurement method as claimed in claim 1, wherein the information relevant to blood pressure is a value relevant to pulse wave propagation measured using electrocardiogram measurement means and photoelectric pulse wave detection means attached to a periphery.

5. The blood flow volume measurement method as claimed in claim 1, further comprising:

calibrating the relationship between the estimated systolic blood pressure, the estimated diastolic blood pressure, the systolic duration, and the diastolic duration based on which the blood flow volume is calculated at said step of calculating the blood flow volume and the blood flow volume according to the blood flow volume measured by an apparatus for measuring blood flow volume that can be used for another calibration.

6. The blood flow volume measurement method as claimed in claim 1, wherein the information relevant to blood pressure is a pulse wave propagation time or a pulse wave propagation velocity.

7. A blood flow volume measurement method of measuring a blood flow volume ejected by cardiac contraction in a vital sign monitoring apparatus, said blood flow volume measurement method comprising the steps of:

calculating estimated systolic blood pressure and estimated diastolic blood pressure from information relevant to blood pressure measured based on the relationship between information relevant to blood pressure and systolic blood pressure and the relationship between information relevant to blood pressure and diastolic blood pressure;

calculating an estimated systolic duration and an estimated diastolic duration of an aorta from a systolic duration and a diastolic duration of a peripheral blood vessel measured based on the relationship between the systolic or diastolic duration in the aorta and the systolic or diastolic duration in the peripheral blood vessel; and

calculating a blood flow volume ejected by cardiac contraction based on the estimated systolic blood pressure, the estimated diastolic blood pressure, the estimated systolic duration, and the estimated diastolic duration calculated.

8. The blood flow volume measurement method as claimed in claim 7, wherein said step of calculating the blood flow volume calculates the cardiac output per unit time using a heart rate or a pulse rate measured.

9. The blood flow volume measurement method as claimed in claim 7, wherein the relationship between information relevant to blood pressure and systolic blood pressure and the relationship between information relevant to blood pressure and diastolic blood pressure are determined by the information relevant to blood pressure measured at blood pressure measuring time with a cuff and the systolic blood pressure and the diastolic blood pressure measured by blood pressure measurement with the cuff.

10. The blood flow volume measurement method as claimed in claim 7, wherein the information relevant to blood pressure is a value relevant to pulse wave propagation measured using electrocardiogram measurement means and photoelectric pulse wave detection means attached to a periphery.

11. The blood flow volume measurement method as claimed in claim 7, wherein the systolic or diastolic duration in the aorta is measured from a pulse wave detected by cuff pulse wave detection means for blood pressure measurement, and wherein the systolic or diastolic duration in the peripheral blood vessel is measured from a pulse wave detected by photoelectric pulse wave detection means attached to a periphery.

12. The blood flow volume measurement method as claimed in claim 7, further comprising:

calibrating the relationship between the estimated systolic blood pressure, the estimated diastolic blood pressure, the systolic duration, and the diastolic duration based on which the blood flow volume is calculated at said step of calculating the blood flow volume and the blood flow volume according to the blood flow volume measured by an apparatus for measuring blood flow volume that can be used for another calibration.

13. The blood flow volume measurement method as claimed in claim 7, wherein the information relevant to blood pressure is a pulse wave propagation time or a pulse wave propagation velocity.

14. A blood flow volume measurement method of measuring a blood flow volume ejected by cardiac contraction in a vital sign monitoring apparatus, said blood flow volume measurement method comprising:

a first step for measuring a predetermined systolic pulse wave area in an aorta, measuring a systolic duration or a diastolic duration in the aorta, and measuring first blood flow volume based on the predetermined systolic pulse wave area and the systolic duration or the diastolic duration;

a second step for calculating estimated systolic blood pressure and estimated diastolic blood pressure from information relevant to blood pressure measured based on the relationship between information relevant to blood pressure and systolic blood pressure and the relationship between information relevant to blood pressure and diastolic blood pressure at the same time as the first blood flow volume is measured, and further measuring a systolic duration and a diastolic duration;

a third step for determining a predetermined coefficient in a predetermined relational expression so that blood flow volume calculated according to the predetermined relational expression from the estimated systolic blood pressure, the estimated diastolic blood pressure, the systolic duration, and the diastolic duration calculated at said second step matches the first blood flow volume measured at said first step;

a fourth step for calculating estimated systolic blood pressure and estimated diastolic blood pressure from information relevant to blood pressure measured based on the relationship between information relevant to blood pressure and systolic blood pressure and the relationship between information relevant to blood pressure and diastolic blood pressure;

a fifth step for measuring a systolic duration and a diastolic duration; and

a sixth step for calculating a blood flow volume based on the estimated systolic blood pressure and the estimated diastolic blood pressure calculated and the systolic duration and the diastolic duration measured according to the predetermined relational expression using the predetermined coefficient determined at said third step.

15. The blood flow volume measurement method as claimed in claim 14, wherein said fifth step calculates an estimated systolic duration and an estimated diastolic duration of an aorta from a systolic duration and a diastolic duration of a peripheral blood vessel measured, based on the relationship between the systolic or diastolic duration in the aorta and the systolic or diastolic duration in the peripheral blood vessel.

16. The blood flow volume measurement method as claimed in claim 15, wherein the systolic or diastolic duration in the aorta is measured from a pulse wave detected by cuff pulse wave detection means for blood pressure measurement, and wherein the systolic or diastolic duration in the peripheral blood vessel is measured from a pulse wave detected by photoelectric pulse wave detection means attached to a periphery.

17. The blood flow volume measurement method as claimed in claim 14, wherein said step of calculating the blood flow volume calculates the cardiac output per unit time using a heart rate or a pulse rate measured.

18. The blood flow volume measurement method as claimed in claim 14, wherein the relationship between information relevant to blood pressure and systolic blood pressure and the relationship between information relevant to blood pressure and diastolic blood pressure are determined by the information relevant to blood pressure measured at blood pressure measuring time with a cuff and the systolic blood pressure and the diastolic blood pressure measured by blood pressure measurement with the cuff.

19. The blood flow volume measurement method as claimed in claim 14, wherein the information relevant to blood pressure is a value relevant to pulse wave propagation measured using electrocardiogram measurement means and photoelectric pulse wave detection means attached to a periphery.

20. The blood flow volume measurement method as claimed in claim 14, wherein the predetermined systolic pulse wave area in the aorta is calculated from a pulse wave detected by cuff pulse wave detection means for blood pressure measurement.

21. The blood flow volume measurement method as claimed in claim 14 further comprising:

calibrating the relationship between the estimated systolic blood pressure, the estimated diastolic blood pressure, the systolic duration, and the diastolic duration based on which the blood flow volume is calculated at said step of calculating the blood flow volume and the blood flow volume according to the blood flow volume measured by an apparatus for measuring blood flow volume that can be used for another calibration.

22. The blood flow volume measurement method as claimed in claim 14, wherein the information relevant to blood pressure is a pulse wave propagation time or a pulse wave propagation velocity.

23. A vital sign monitoring apparatus comprising:

estimated blood pressure calculation means for calculating estimated systolic blood pressure and estimated diastolic blood pressure from information relevant to blood pressure measured based on the relationship between information relevant to blood pressure and systolic blood pressure and the relationship between information relevant to blood pressure and diastolic blood pressure;

systolic and diastolic duration measurement means for measuring a systolic duration and a diastolic duration; and

blood flow volume calculation means for calculating a blood flow volume ejected by cardiac contraction based on the estimated systolic blood pressure and the estimated diastolic blood pressure calculated and the systolic duration and the diastolic duration measured.

24. The vital sign monitoring apparatus as claimed in claim 23 further comprising:

input means for externally inputting values for calibrating the relationship between the estimated systolic blood pressure, the estimated diastolic blood pressure, the systolic duration, and the diastolic duration based on which said blood flow volume calculation means calculates the blood flow volume, and the blood flow volume.

25. The vital sign monitoring apparatus as claimed in claim 23 further comprising:

alarm output means for outputting an alarm when the blood flow volume calculated by said blood flow volume calculation means changes beyond a predetermined threshold value.

26. The vital sign monitoring apparatus as claimed in claim 25 wherein the alarm output means outputs the contents containing an instruction notifying to calibrate the relationship between the estimated systolic blood pressure, the estimated diastolic blood pressure, the systolic duration, and the diastolic duration based on which said blood flow volume calculation means calculates the blood flow volume, and the blood flow volume.

27. A blood flow volume measurement method of measuring a blood flow volume ejected by cardiac contraction in a vital sign monitoring apparatus, said blood flow volume measurement method comprising the steps of:

calculating estimated blood pressures at the different levels from the measured information relevant to blood pressure on the basis of the relationship between blood pressures at different levels and information relevant to blood pressure;

measuring a systolic duration and a diastolic duration; and

calculating a blood flow volume based on the estimated blood pressure calculated and the systolic duration and the diastolic duration measured.

28. The blood flow volume measurement method as claimed in claim 27, wherein any two of systolic blood pressure, diastolic blood pressure, mean blood pressure, end systolic blood pressure, mean systolic blood pressure, or mean diastolic blood pressure are used as the blood pressures at the different levels.

29. The blood flow volume measurement method as claimed in claim 27, wherein the information relevant to blood pressure is information relevant to pulse wave propagation time.

30. A blood flow volume measurement method of measuring a blood flow volume ejected by cardiac contraction in a vital sign monitoring apparatus, said blood flow volume measurement method comprising the steps of:

calculating estimated blood pressures at the different levels from the measured information relevant to blood pressure on the basis of the relationship between blood pressures at different levels and information relevant to blood pressure;

calculating an estimated systolic duration and an estimated diastolic duration of an aorta from a systolic duration and a diastolic duration of a peripheral blood vessel measured based on the relationship between the systolic or diastolic duration in the aorta and the systolic or diastolic duration in the peripheral blood vessel; and

calculating a blood flow volume based on the estimated systolic blood pressure, the estimated diastolic blood pressure, the systolic duration, and the diastolic duration calculated.

31. The blood flow volume measurement method as claimed in claim 30, wherein any two of systolic blood pressure, diastolic blood pressure, mean blood pressure, end systolic blood pressure, mean systolic blood pressure, or mean diastolic blood pressure are used as the blood pressures at the different levels.

32. The blood flow volume measurement method as claimed in claim 30, wherein the information relevant to blood pressure is information relevant to pulse wave propagation time.

33. A blood flow volume measurement method of measuring a blood flow volume ejected by cardiac contraction in a vital sign monitoring apparatus, said blood flow volume measurement method comprising:

a first step for measuring a predetermined systolic pulse wave area in an aorta, measuring a systolic duration or a diastolic duration in the aorta, and measuring first blood flow volume based on the predetermined systolic pulse wave area and the systolic duration or the diastolic duration;

a second step, calculating estimated blood pressures at the different levels from the measured information relevant to blood pressure, based on the relationship between blood pressures at different levels and information relevant to blood pressure, at the same time as the first blood flow volume is measured, and further measuring a systolic duration and a diastolic duration;

a third step for determining a predetermined coefficient in a predetermined relational expression so that blood flow volume calculated according to the predetermined relational expression from the estimated systolic blood pressure, the estimated diastolic blood pressure, the systolic duration, and the diastolic duration calculated at said second step matches the first blood flow volume measured at said first step;

a fourth step for calculating estimated systolic blood pressure and estimated diastolic blood pressure from information relevant to blood pressure measured based on the relationship between blood pressures at different levels and information relevant to blood pressure;

a fifth step for measuring a systolic duration and a diastolic duration; and

a sixth step for calculating a blood flow volume based on the estimated systolic blood pressure and the estimated diastolic blood pressure calculated and the systolic duration and the diastolic duration measured according to the predetermined relational expression using the predetermined coefficient determined at said third step.

34. The blood flow volume measurement method as claimed in claim 33, wherein any two of systolic blood pressure, diastolic blood pressure, mean blood pressure, end systolic blood pressure, mean systolic blood pressure, or mean diastolic blood pressure are used as the blood pressures at the different levels.

35. The blood flow volume measurement method as claimed in claim 33, wherein the information relevant to blood pressure is information relevant to pulse wave propagation time.