Electronic sphygmomanometer

DETAILED DESCRIPTION What is claimed is: 1.
An electronic sphygmomanometer comprising: an inflatable cuff; a pressure displaying means for displaying pressure in said cuff; a microphone attached to said cuff; an indicating means for indicating the appearance of Korotkov sounds; and, an indicating signal producing means for supplying indicating signals to said indicating means, including a preamplifying circuit for amplifying output signals of said microphone, a bandpass filtering circuit receiving the output of said pre-amplifying circuit and passing Korotkov sound signals, said bandpass filtering circuit having a passband with a low cutoff frequency of 40 Hz and a high cutoff frequency of 90 Hz, a detecting circuit for detecting said Korotkov sound signals, a discriminating circuit for discriminating output signals of said detecting circuit, and an amplifying circuit for amplifying the output of said discriminating circuit.
2.
The electronic sphygmomanometer of claim 1, wherein said indicating means consists of a light emission diode which intermittently emits light in response to said detected Korotkov sound signals.




Description:
BACKGROUND OF THE INVENTION This invention relates to an electronic sphygmomanometer for electrically discriminating Korotkov sounds.
The typical recently developed electronic sphygmomanometer has a microphone incorporated in an inflatable cuff which occludes blood flow.
The blood pressure of an individual is measured when the cuff is wrapped around the arm of an individual to position the microphone over or adjacent an artery below the blood-occluding portion of a cuff.
The microphone receives Korotkov sounds, as well as pulse sounds and other external noise, and converts this to electrical signals.
The Korotkov sound signals are discriminated through a filtering circuit and applied to the systolic blood pressure indicator and diastolic blood pressure indicator respectively.
However, prior art sphygmomanometers require complex electrical circuits and are expensive