Abstract: In an electronic blood pressure meter for measuring blood pressure from a finger, there is provided a photoelectric sensor including a light emitting element and a light receiving element for detecting pulse wave components from a finger placed in a cuff. Since the variation of the DC component of the pulse wave from one person to another may exceed the linear range of pulse wave measurement, the brightness level of the light emitting element is adjusted according to the level of the DC component contained in the output from the light receiving element. Thereby, favorable extraction of the variational component of the pulse wave is made always within an accurate range of pulse wave measurement.

Abstract: In an electronic blood pressure meter, pressurization requirement of the cuff is minimized by predicting a systolic blood pressure level from blood vessel information which may be obtained with an initial cuff pressure which is lower than the systolic blood pressure. The prediction of the systolic blood pressure may be based on a diastolic blood pressure, a maximum pulse wave amplitude value, on other pulse wave amplitude value, a cuff pressure value corresponding to the other pulse wave amplitude value and an empirically obtained parameter. Thus, since the cuff pressure is not increased any more than required, the discomfort to the subject person and the time period required for blood pressure measurement are both minimized and the accuracy of blood pressure measurement is improved.

Abstract: In an electronic blood pressure meter, artifacts or disturbances of blood pressure measurement due to the motions of the arm or the body of the person whose blood pressure is to be measured is detected from the level of a pulse wave signal. If the pulse wave signal continues to be above a certain reference level for more than a certain threshold time period, it is determined to be indicative of the presence of an artifact which prevents accurate measurement of blood pressure. This process of detecting an artifact can be conveniently implemented as an interruption routine of a microprocessor. When such an artifact is detected, a warning signal may be issued and the cuff may be rapidly vented so that the renewed measurement can be carried out without any further ado.

Abstract: In an electronic blood pressure meter, there are included a cuff adapted to be fitted around the arm of a patient whose blood pressure is to be measured and formed with a cavity, a device for pressurizing the cavity in the cuff, a device for gradually depressurizing the cavity in the cuff, a device for sensing the pressure in the cavity in the cuff and for producing an output signal representative thereof, a device for detecting a pulse wave component in the output signal produced by the sensing device, a device for determining the amplitude of the thus detected pulse wave component, a device for determining values for systolic blood pressure and diastolic blood pressure according to the thus determined amplitude of the pulse wave component and according to the output signal produced by the pressure sensing device, and a device for performing compensation relating to the values for systolic blood pressure and diastolic blood pressure.

Abstract: In an electronic blood pressure meter for measuring blood pressure from a finger, there is provided a photoelectric sensor for detecting presence of a finger in the cuff. Thereby, it is made possible to positively avoid inflating the cuff without placing a finger therein and to prevent rupture and other damages to the cuff. In particular, since either a light emitting element or a light receiving element of the photoelectric sensor for detecting a finger is common to that of a photoelectric pulse wave detecting device incorporated in the cuff, the structure of the cuff is simplified and the manufacturing cost is reduced.