Blood pressure monitoring system

• US 5,564,427 A
• Filed: 03/30/1995
• Issued: 10/15/1996
• Est. Priority Date: 03/30/1994
• Status: Expired due to Term

• Current Assignee: Nihon Kohden Corporation
• Original Assignee: Nihon Kohden Corporation
• Inventors: Sugo, Yoshihiro, Hosaka, Hidehiro, Sakata, Hiroshi, Aso, Shigeru
• Primary Examiner(s): Sykes, Angela D.
• Assistant Examiner(s): NASSER, ROBERT L
• Application Number:
  US08/413,850
• Time in Patent Office: 565 Days
• Field of Search: 128/677, 128/680-683, 128/687
• US Class Current: 600/494
• CPC Class Codes: A61B 5/02255 the pressure being controlled by plethysmographic signals, e.g. derived from optical sensors
• CPC Class Codes: A61B 5/0285 Measuring or recording phase velocity of blood waves

Abstract

A blood pressure monitoring system includes a blood pressure measurement device for measuring blood pressure using a cuff, a memory for storing an externally inputted pulse wave propagation time fluctuation threshold, a time interval detection reference point detection section for detecting a time interval detection reference point in a pulse wave on the side of aortae of a living organism, 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 section and the pulse wave detection section, an operation device for calculating a pulse wave propagation fluctuation from two measured pulse wave propagation times, a judgment device for judging whether or not the calculated pulse wave propagation time fluctuation exceeds the pulse wave propagation time fluctuation threshold read from the memory, and a control device for controlling the blood pressure measurement device based on an output of the judgment device so that the blood pressure of a subject is measured using the cuff.

Claims

1. A blood pressure monitoring system comprising:

blood pressure measurement means for measuring blood pressure using a cuff;

a memory for storing an externally inputted pulse wave propagation time fluctuation threshold;

time interval detection reference point detection means for detecting a time interval detection reference point in an aortic pulse wave of a subject;

pulse wave detection means for detecting a pulse wave in peripheral blood vessels appearing with a time lag with respect to the aortic pulse wave;

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 calculating a pulse wave propagation fluctuation from two measured pulse wave propagation times;

judgment means for judging whether or not the calculated pulse wave propagation time fluctuation exceeds the pulse wave propagation time fluctuation threshold read from the memory; and

control means for controlling the blood pressure measurement means based on an output of the judgment means so that the blood pressure of a subject is measured using the cuff.

2. The blood pressure monitoring system according to the claim 1, wherein the memory stores a blood pressure fluctuation threshold, and further comprising:

second operation means for calculating constants inherent in the subject by dividing a difference between two blood pressure values obtained by the blood pressure measurement means by a difference between the two measured pulse wave propagation times;

third operation means for updating the pulse wave propagation time fluctuation threshold within the memory by dividing the blood pressure fluctuation threshold read from the memory by the at least on of said calculated constants inherent in the subject; and

auxiliary control means for controlling the operation of updating the pulse wave propagation time fluctuation threshold.

3. A blood pressure monitoring method comprising the steps of:

measuring blood pressure using a cuff;

storing an externally inputted pulse wave propagation time fluctuation threshold in a memory;

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

detecting a pulse wave in peripheral blood vessels appearing with a time lag with respect to the aortic pulse wave;

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;

calculating a pulse wave propagation fluctuation from two measured pulse wave propagation times;

judging whether or not the calculated pulse wave propagation time fluctuation exceeds the pulse wave propagation time fluctuation threshold read from the memory; and

controlling the blood pressure measurement means based on an output of the judgment means so that the blood pressure of a subject is measured using the cuff.

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

measuring blood pressure using a cuff;

storing a pulse wave propagation time fluctuation threshold and a blood pressure fluctuation threshold in a memory, the thresholds being inputted from an external means;

detecting a time interval detection reference point in an aortic pulse wave of a living organism;

detecting a pulse wave in peripheral blood vessels appearing with a time lag with respect to the aortic pulse wave;

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;

calculating a pulse wave propagation time fluctuation from two measured pulse wave propagation times;

calculating constants inherent in said living organism by dividing a difference between two blood pressure values obtained by the blood pressure measurement means by a difference between the two measured pulse wave propagation times;

updating the pulse wave propagation time fluctuation threshold within the memory by dividing the blood pressure fluctuation threshold read from the memory by the at least on of said calculated constants inherent in the subject;

controlling the operation of updating the pulse wave propagation time fluctuation threshold;

judging whether or not the calculated pulse wave propagation time fluctuation exceeds the pulse wave propagation time fluctuation threshold read from the memory; and

controlling the blood pressure measurement means based on an output of the judgment means so that the blood pressure of the subject is measured using the cuff.