Patent ID: 6171254
Filing Date: 2001-01-09
Classification: A61B

Abstract:
An automatic, non-invasive blood pressure measuring device of the type which detects blood pressure pulses in a patient's appendage, comprising:a cuff for constricting blood flow in the patient's appendage;a pump connected to the cuff for inflation thereof in response to a pump control signal;valve means connected to the cuff for deflation thereof in response to a valve control signal;a pressure sensing means connected to the cuff to sense pressure in the cuff and to send a pressure signal indicating a pressure-time characteristic of said cuff in response thereto;microprocessor means connected to said pump, said valve means and said pressure sensing means, including means to observe the initial pressure-time characteristic of said cuff during an observed inflation period in which the pressure of the cuff is increased to a level less than a target pressure needed to take a blood pressure reading; andsaid microprocessor means including means for determining the cuff size by comparing the initial pressure-time characteristic of said cuff with a set of stored pressure-time characteristics of cuffs of known sizes, and means for determining, in response to said cuff size determination, a cuff inflation rate, a cuff deflation rate and an initial target pressure, said microprocessor means sending control signals to said pump to inflate said cuff to said target pressure according to said cuff inflation rate, and to deflate said cuff at said deflation rate, using said at least one deflation pressure drop step.