Electronic blood pressure measurment device

• US 5,680,867 A
• Filed: 02/13/1995
• Issued: 10/28/1997
• Est. Priority Date: 04/02/1993
• Status: Expired due to Term

• Current Assignee: Hideaki Shimazu, Hidetaka Shimizu, Masaru Komatsu, Noriyuki Yamaguchi
• Original Assignee: Hideaki Shimazu, Hidetaka Shimizu, Masaru Komatsu, Noriyuki Yamaguchi
• Inventors: Shimizu, Hidetaka, Shimazu, Hideaki, Komatsu, Masaru, Yamaguchi, Noriyuki
• Primary Examiner(s): NASSER, ROBERT L
• Application Number:
  US08/347,428
• Time in Patent Office: 988 Days
• Field of Search: 128/672, 128/677, 128/680-3, 128/687-690, 128/713
• US Class Current: 600/490
• CPC Class Codes: A61B 5/02116 of pulse wave amplitude A61B5/02225 takes precedence
• CPC Class Codes: A61B 5/022 by applying pressure to close blood vessels, e.g. against the skin; Ophthalmodynamometers
• CPC Class Codes: A61B 5/02225 using the oscillometric method
• CPC Class Codes: A61B 5/7264 Classification of physiological signals or data, e.g. using neural networks, statistical classifiers, expert systems or fuzzy systems neural networks per se G06N3/00; expert systems per se G06N5/00
• CPC Class Codes: G16H 50/20 for computer-aided diagnosis, e.g. based on medical expert systems

Abstract

In an electronic blood pressure measurement device which is arranged to extract pulse waves from the measured cuff pressure, a pulse wave pattern is generated from the pulse wave amplitude and pulse wave interval data and this pulse wave pattern is compared with reference patterns to classify the pattern in order to accurately obtain biological information other than the blood pressure. Blood pressure amplitudes PA(i) are computed from the measured cuff pressures C(i) and a pulse wave pattern is generated (35) on the basis of this pulse wave amplitude data and this pulse wave pattern is classified into a plurality of reference patterns (37) according to reference patterns or reference values (36). Here, the reference patterns or reference values are set as hemodynamic references based on dynamic characteristics of the blood vessel or cardiac output characteristics. The pulse wave pattern is normalized as necessary to extract only the shape factors of the pattern, is displayed as a measured pattern corresponding to a reference pattern and is compared with the reference patterns in terms of shape. Also, besides the shape factors, the absolute values of pulse wave amplitudes and systolic pressures are used as references for pattern classification.

Claims

1. An electronic pressure detecting device for monitoring hemodynamic states of a patient based on dynamic characteristics of blood vessels or cardiac output characteristics comprising:

a cuff for applying cuff pressure to said patient;

pressure detection means for detecting said cuff pressure and pulse waves overlaid on said cuff pressure while said cuff pressure is gradually increased decreased;

pulse wave extraction means for extracting pulse wave components from said detected cuff pressure;

pulse wave amplitude detection means for detecting pulse wave amplitudes of said extracted pulse wave components;

pulse wave interval detection means for detecting pulse wave intervals which correspond to time intervals or pressure intervals between adjacent extracted pulse wave components;

pulse wave pattern generation means for generating pulse wave patterns based on said pulse wave amplitudes and said pulse wave intervals;

pattern classification means for classifying said pulse wave patterns into one or more categories based on comparison with a plurality of predetermined hemodynamic reference patterns that correspond to particular dynamic characteristics of blood vessels or cardiac output characteristic each category representing a different hemodynamic condition; and

display means for displaying said generated pulse wave patterns and information about said one or more categories into which said pulse wave patterns are classified.

3. An electronic pressure detecting device as set forth in claim 1 or in claim 2, wherein said pattern classification means is provided with means for detecting numbers of peaks or degrees of disturbance of said pulse wave patterns for use as part of said reference patterns during classification of said pulse wave patterns.

4. An electronic pressure detecting device as set forth in claim 1 or in claim 2, wherein said pattern classification means is provided with means for detecting peak widths of said pulse wave patterns for use as part of said reference patterns during classification of said pulse wave patterns.

5. An electronic pressure detecting device as set forth in claims 1 or in claim 2, further comprising blood pressure detection means for detecting at least systolic pressure based on said extracted pulse wave components or said generated pulse wave patterns, wherein said pattern classification means classifies said pulse wave patterns using said detected systolic pressure as part of said reference patterns.

2. An electronic pressure detecting device for monitoring hemodynamic states of a patient based on dynamic characteristics of blood vessels or cardiac output characteristics comprising:

a cuff for applying cuff pressure to said patient;

pressure detection means for detecting said cuff pressure and pulse waves overlaid on said cuff pressure while said cuff pressure is gradually increased or decreased;

pulse wave extraction means for extracting pulse wave components from said detected cuff pressure;

pulse wave amplitude detection means for detecting pulse wave amplitudes of said extracted pulse wave components;

pulse wave pattern generation means for generating pulse wave patterns that graphically express variations in said detected pulse wave amplitudes while said cuff pressure is gradually decreased or increased;

pattern classification means for classifying said pulse wave patterns into one or more categories based on comparison with a plurality of predetermined hemodynamic reference patterns that correspond to particular dynamic characteristics of blood vessels or cardiac output characteristic each category representing a different hemodynamic condition; and

display means for displaying said generated pulse wave patterns and information about said one or more categories into which said pulse wave patterns are classified.