Noninvasive blood pressure monitoring transducer

• US 4,423,738 A
• Filed: 11/04/1977
• Issued: 01/03/1984
• Est. Priority Date: 11/04/1977
• Status: Expired due to Term

• Current Assignee: SRI International, Inc.
• Original Assignee: SRI International, Inc.
• Inventors: Newgard, Peter M.
• Primary Examiner(s): Howell, Kyle L.
• Assistant Examiner(s): Jaworski, Francis J.
• Application Number:
  US05/848,753
• Time in Patent Office: 2,251 Days
• Field of Search: 128/2.05 A, 128/2.05 B, 128/2.05 D, 128/2.05 E, 128/2.05 M, 128/2.05 N, 128/2.05 Q, 128/2.05 R, 128/2.05 T, 128/662, 128/672 , 128/673-675, 128/677, 128/687-690, 128/714, 73/172, 73/141 A, 73/709, 73/716
• 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 5/02116 of pulse wave amplitude A61B5/02225 takes precedence

Abstract

Intra-arterial blood pressure is noninvasively measured and monitored by an electromechanical force sensor which is made up of an array of individual force sensing elements, each of which has at least one dimension smaller than the lumen of the underlying artery wherein blood pressure is to be measured, and the individual force sensitive element which generates the waveform of maximum amplitude is used to monitor blood pressure.

Claims

1. In a system for the continuous external measurement of blood pressure in an underlying artery comprising at least one transducer array having a multiplicity of individual pressure sensitive elements, each of said individual pressure sensitive elements in said array having at least one dimension smaller than the lumen of the underlying artery in which blood pressure is measured and each individual pressure sensitive element being capable of producing a continuous waveform having an amplitude which is a function of blood pressure in an underlying artery, means responsive to the waveform output of all of the said individual pressure sensitive elements to select the single one of the said transducer elements which is best positioned in the arterial pressure sensing environment for blood pressure measurement, and means to utilize the output of only the said single one of the said individual pressure sensitive elements to measure blood pressure and produce a continuous waveform having an amplitude which is a function of blood pressure in an underlying artery.

2. In a system for the continuous external measurement of blood pressure in an artery as defined in claim 1, wherein each of said individual pressure sensitive elements in said array has at least the said one dimension less than approximately 0.50 mm.

3. In a system for the continuous external measurement of blood pressure in an artery as defined in claim 1, wherein the said means responsive to the waveform output of all of the said individual pressure sensitive elements comprises means for selecting the said only one of said individual pressure sensitive elements of said array which generates the waveform of maximum amplitude.