Device and method for determining systolic blood pressure

• US 4,735,213 A
• Filed: 08/20/1986
• Issued: 04/05/1988
• Est. Priority Date: 08/21/1985
• Status: Expired due to Fees

• Current Assignee: Omron Tateisi Electronics Co. (Omron Corporation)
• Original Assignee: Omron Tateisi Electronics Co. (Omron Corporation)
• Inventors: Shirasaki, Osamu
• Primary Examiner(s): Jaworski, Francis J.
• Application Number:
  US06/898,334
• Time in Patent Office: 594 Days
• Field of Search: 128/680-683, 364/417, 364/415
• US Class Current: 600/494
• CPC Class Codes: A61B 5/02116 of pulse wave amplitude A61B5/02225 takes precedence
• CPC Class Codes: A61B 5/02225 using the oscillometric method
• CPC Class Codes: A61B 5/0225 the pressure being controlled by electric signals, e.g. derived from Korotkoff sounds

Abstract

This electronic blood pressure measurement device includes a cuff with pressurization, draining, and sensing means, a means for generating from the cuff pressure signal a pulse wave signal, and a means for determining for the patient a value for systolic blood pressure. This blood pressure determining means detects an interval during which the amplitude of the pulse wave signal increases substantially linearly, and sets the systolic blood pressure value using the pulse wave amplitude at the end of that interval. Optionally but desirably, this means locates an approximate start of the linear interval as being a point where the pulse wave amplitude has a certain relation to the pulse wave amplitude at the end of the interval, and determines the value for systolic blood pressure to be the cuff pressure at such an approximate start of the interval. The approximate start of the interval may be determined as the point where the pulse wave amplitude is a certain proportion of the pulse wave amplitude at the end of the interval; and this certain proportion may be approximately 60%. An operational method for this device is also disclosed.

Claims

1. An electronic blood pressure measurement device, comprising:

(a) a cuff means for being fitted around the arm of a patient;

(b) a means for selectively pressurizing said cuff means with fluid, so as to squeeze said arm of said patient;

(c) a means for selectively draining said fluid from said cuff means either at a relatively rapid rate or at a relatively slow rate;

(d) a means for sensing the pressure of said fluid in said cuff means and for producing a pressure output signal representative thereof;

(e) a means for receiving said pressure output signal from said cuff pressure sensing means and for generating therefrom An Associated pulse wave signal representative of the pulse wave of the patient; and

(f) a blood pressure determining means for receiving said pressure output signal and said pulse wave signal and for determining for the patient a value for systolic blood pressure as a blood pressure measurement, said blood pressure determining means comprising means for determining an interval during which the amplitude of said pulse wave signal changes in a substantially linear manner and a higher amplitude end of said interval, and means for setting said systolic blood pressure value at a value corresponding to that pressure output signal associated with a pulse wave signal amplitude which is a fraction of the pulse wave signal amplitude at said end of said interval.

2. An electronic blood pressure measurement device according to claim 1, wherein said fraction is approximately six tenths.

3. A method for operating an electronic blood pressure measurement device comprising the step of:

(a) fitting a cuff around an arm of a patient;

(b) selectively pressurizing said cuff with fluid, so as to squeeze said arm of said patient;

(c) selectively draining said fluid from said cuff either at a relatively rapid rate or at a relatively slow rate;

(d) sensing the pressure of said cuff and producing an output signal representative thereof;

(e) receiving said output signal respresentative of pressure from said cuff and generating therefrom an associated signal representative of the pulse wave of said patient;

(f) determining an interval in which the amplitude of said pulse wave signal changes in a substantially linear manner and a higher amplitude of end of said interval, and

(g) setting a systolic blood pressure value as a blood pressure measurement for the patient at a value corresponding to that pressure output signal associated with a pulse wave signal amplitude which is a fraction of the pulse wave signal amplitude at said end of said interval.

4. A method for operating an electronic blood pressure measurement device according to claim 3, wherein said fraction is approximately sixtenth.