Method and apparatus for continuously and noninvasively measuring the blood pressure of a patient

• US 5,163,438 A
• Filed: 09/24/1990
• Issued: 11/17/1992
• Est. Priority Date: 11/14/1988
• Status: Expired due to Term

• Current Assignee: Masimo Corporation
• Original Assignee: Paramed Technology Incorporated
• Inventors: Gordon, Deborah C., Brunot, Frank A.
• Primary Examiner(s): JAWORSKI, FRANCIS J
• Application Number:
  US07/586,794
• Time in Patent Office: 785 Days
• Field of Search: 128/680-683, 128/660.02, 128/24 A, 73/1 DV
• US Class Current: 600/490
• CPC Class Codes: A61B 5/022 by applying pressure to close blood vessels, e.g. against the skin; Ophthalmodynamometers

Abstract

In the present invention, a method and an apparatus for measuring the blood pressure of a patient continuously and non-invasively is disclosed. The blood pressure is determined by measuring the harmonic frequencies and displacements of an arterial wall of the patient. The measurements are then calibrated against an absolute blood pressure supplied by an operator at a particular time. The blood pressure is then the sum of the relative changes of the measurements and the absolute blood pressure.

Claims

1. A medical instrument comprising:

an electromechanical sensing means for generating a signal in response to mechanical motion detected by said sensing means, and for moving in response to an electrical signal supplied thereto;

means for supplying an excitation signal to said sensing means to cause motion in said sensing means; and

means for detecting a response signal generated by said sensing means moving in response to said excitation signal supplied thereto,

wherein said detection of said response signal is indicative of the operational readiness of said sensing means.

2. A method of testing the operational readiness of an electromechanical sensing means for placement on a particular location of a patient, said sensing means generating a response signal in response to the detection of mechanical motion of said sensing means, said sensing means also moving in response to an excitation signal applied thereto;

said method comprising the steps of;

positioning said sensing means on said patient;

supplying an excitation signal to said sensing means;

moving said sensing means in response to said excitation signal; and

detecting said response signal in response to the movement of said sensing means,

wherein the detection of said response signal is indicative of the operational readiness of the sensing means.