Blood pressure measuring apparatus

• US 5,709,212 A
• Filed: 03/30/1995
• Issued: 01/20/1998
• Est. Priority Date: 03/30/1994
• Status: Expired due to Fees

• Current Assignee: Nihon Kohden Corporation
• Original Assignee: Nihon Kohden Corporation
• Inventors: Sugo, Yoshihiro, Sohma, Takeshi
• Primary Examiner(s): Nasser, Robert L.
• Application Number:
  US08/413,223
• Time in Patent Office: 1,027 Days
• Field of Search: 128/672, 128/677, 128/680-7
• US Class Current: 600/485
• 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 5/352 Detecting R peaks, e.g. for synchronising diagnostic apparatus; Estimating R-R interval

Abstract

A blood pressure measuring device includes: a memory for storing a standard constant α; an input means for inputting a correcting blood pressure value; a time interval reference point detection section for detecting a time interval detection reference point in a pulse wave on the side of aortae; a pulse wave detection section for detecting a pulse wave on the side of peripheral blood vessels appearing with a time lag with respect to the pulse wave on the side of aortae; a pulse wave propagation time measurement section for measuring a pulse wave propagation time based on respective detected outputs from the time interval detection reference point detection means and the pulse wave detection means; an operation means for determining a constant β using the blood pressure value for calibration, pulse wave propagation time, and standard constant α inputted for calibration; an operation means for calculating the blood pressure value from the pulse wave propagation time measured at a predetermined time interval for measuring a circadian blood pressure fluctuation, and the standard constants α, β; a memory for consecutively storing the measured pulse wave propagation time and the blood pressure value calculated from the pulse wave propagation time; and an external output connector for outputting at least the blood pressure value and pulse wave propagation time data as a result of the circadian blood pressure fluctuation measurement.

Claims

1. A blood pressure measuring apparatus comprising:

a memory for storing a constant α

by which a pulse wave propagation time is multiplied in calculating a blood pressure value from the pulse wave propagation time;

input means for inputting a blood pressure value for calibration;

time interval detection reference point detecting means for detecting a time interval detection reference point in a pulse wave on a side of an aortae of a living organism;

pulse wave detection means for detecting a pulse wave on a side of peripheral blood vessels appearing with a time lag with respect to the pulse wave on the side of the aortae;

pulse wave propagation time measurement section for measuring a pulse wave propagation time based on respective detected outputs from the time interval detection reference point detection means and the pulse wave detection means;

first operation means for determining a constant β

to be added in calculating the blood pressure value from the pulse wave propagation time using the inputted calibrated blood pressure value, a single pulse wave propagation time measured for calibration, and the prestored constant α

;

second operation means for calculating the blood pressure value from the pulse wave propagation time measured at a predetermined time interval for measuring a circadian blood pressure fluctuation, the constant α

, and the constant β

;

memory for consecutively storing the measured pulse wave propagation time and the blood pressure value calculated from the pulse wave propagation time; and

output means for outputting at least one of the blood pressure value and pulse wave propagation time data stored in the memory as a result of the circadian blood pressure fluctuation measurement.

2. The blood pressure measuring apparatus as recited in claim 1 wherein, the time interval detection reference point detection means includes an electrode to be attached to a subject, and an electrocardiographic R wave detection section to which the electrode is connected.

3. The blood pressure measuring apparatus as recited in claim 1 wherein, the time interval detection reference point detection means includes a pulse wave detection section connected to at least one of a photoelectric pulse wave sensor and a pressure pulse wave sensor.

4. A blood pressure measuring method comprising the steps of:

storing a first constant by which a pulse wave propagation time is multiplied in calculating a blood pressure value from the pulse wave propagation time;

inputting a blood pressure value of a subject for calibration;

detecting a time interval detection reference point in a pulse wave on a side of an aortae of a living organism;

detecting a pulse wave on a side of peripheral blood vessels appearing with a time lag with respect to the pulse wave on the side of the aortae;

measuring a pulse wave propagation time based on respective detected outputs from the time interval detection reference point and the pulse wave on the side of the peripheral blood vessels appearing with a time lag with respect to the pulse wave on the side of the aortae;

determining a second constant to be used in calculating the blood pressure value from the pulse wave propagation time using the blood pressure value input for calibration., a single pulse wave propagation time measured for calibration, and the prestored first constant;

calculating the blood pressure value from the pulse wave propagation time measured at a predetermined time interval for measuring a circadian blood pressure fluctuation, the stored first constant, and the already determined second constant;

consecutively storing the measured pulse wave propagation time and the blood pressure value calculated from the pulse wave propagation time; and

outputting at least one of the blood pressure value and pulse wave propagation time data stored in the memory as a result of the circadian blood pressure fluctuation measurement.

5. A blood pressure measuring apparatus comprising:

an input means for inputting a blood pressure value for calibration;

time interval detection reference point detection means for detecting a time interval detection reference point in a pulse wave on a side of an aortae of a living organism;

pulse wave detection means for detecting a pulse wave on a side of peripheral blood vessels appearing with a time lag with respect to the pulse wave on the side of the aortae;

pulse wave propagation time measurement section for measuring a pulse wave propagation time based on respective detected outputs from the time interval detection reference point detection means and the pulse wave detection means;

first operation means for determining a constant β

to be added in calculating the blood pressure value from the pulse wave propagation time using the inputted calibrated blood pressure value, a single pulse wave propagation time measured for calibration, and a constant α

;

second operation means for calculating the blood pressure value from the pulse wave propagation time measured at a predetermined time interval for measuring a circadian blood pressure, fluctuation, the constant α

, and the constant β

;

memory for consecutively storing the measured pulse wave propagation time and the blood pressure value calculated from the pulse wave propagation time; and

output means for outputting at least one of the blood pressure value and pulse wave propagation time data stored in the memory as a result of the circadian blood pressure fluctuation measurement, wherein the improvement comprises;

a memory for storing said constant α

by which a pulse wave propagation time is multiplied in calculating a blood pressure value from the pulse wave propagation time.

6. A blood pressure measuring method comprising the steps of:

inputting a blood pressure value of a subject for calibration;

detecting a time interval detection reference point in a pulse wave on a side of an aortae of a living organism;

detecting a pulse wave on a side of peripheral blood vessels appearing with a time lag with respect to the pulse wave on the side of the aortae;

measuring a pulse wave propagation time based on respective detected outputs from the time interval detection reference point and the pulse wave on the side of the peripheral blood vessels appearing with a time lag with respect to the pulse wave on the side of the aortae;

determining a second constant to be used in calculating the blood pressure value from the pulse wave propagation time using the inputted blood pressure value for calibration, a single pulse wave propagation time measured for calibration, and a first constant;

calculating the blood pressure value from the pulse wave propagation time measured at a predetermined time interval for measuring a circadian blood pressure fluctuation, the first constant, and the previously determined second constant;

consecutively storing the measured pulse wave propagation time and the blood pressure value calculated from the pulse wave propagation time; and

outputting at least one of the blood pressure value and the pulse wave propagation time data stored in the memory as a result of the circadian blood pressure fluctuation measurement, wherein the improvement comprises;

prior to the step of inputting a blood pressure value of a subject for calibration, storing the first constant by which the pulse wave propagation time is multiplied in calculating the blood pressure value from the pulse wave propagation time.