Electronic blood pressure monitor

An electronic blood pressure monitor comprising:

• a cuff configured to be mounted on a predetermined portion of a subject for pressurizing an artery of the subject;
• a cuff pressure controller for controlling a cuff pressure inside the cuff;
• a pressure detector for detecting the cuff pressure;
• a pulse wave detector for detecting a pulse wave of the artery that is pressured by the cuff;
• a wave feature calculating unit for calculating a wave feature value of the pulse wave detected by the pulse wave detector;
• a function memory that stores a two-parameter function having the wave feature value and a relative cuff pressure as parameters, the relative cuff pressure being a pressure difference between the detected cuff pressure and a blood pressure of the subject;
• a single-parameter function generating unit that generates a single-parameter function by setting the wave feature value of the two-parameter function at the calculated wave feature value of the pulse wave detected by the pulse wave detector so that the single-parameter function has the relative cuff pressure as a parameter;
• a relative cuff pressure determining unit that determines the relative cuff pressure corresponding to the pulse wave detected by the pulse wave detector as a maximum of the single-parameter function or a maximum of a function generated based on the single-parameter function;
• a blood pressure calculating unit that calculates the blood pressure of the subject by subtracting the determined relative cuff pressure from the cuff pressure detected by the pressure detector when the pulse wave detector detects the pulse wave, and
• a blood pressure averaging unit that calculates an average blood pressure,
• wherein the cuff pressure controller changes the cuff pressure so that the cuff pressure approaches the average blood pressure when the average blood pressure is not equal to the cuff pressure detected by the pressure detector when the pulse wave detector detects the pulse wave, and the pulse wave detector detects the pulse wave at the cuff pressure changed by the cuff controller.

An electronic blood pressure monitor comprising:

• a cuff configured to be mounted on a predetermined portion of a subject for pressurizing an artery of the subject;
• a cuff pressure controller for controlling a cuff pressure inside the cuff;
• a pressure detector for detecting the cuff pressure;
• a pulse wave detector for detecting a pulse wave of the artery that is pressured by the cuff;
• a wave feature calculating unit for calculating a wave feature value of the pulse wave detected by the pulse wave detector;
• a function memory that stores a two-parameter function having the wave feature value and a relative cuff pressure as parameters, the relative cuff pressure being a pressure difference between the detected cuff pressure and a blood pressure of the subject;
• a single-parameter function generating unit that generates a single-parameter function by setting the wave feature value of the two-parameter function at the calculated wave feature value of the pulse wave detected by the pulse wave detector so that the single-parameter function has the relative cuff pressure as a parameter;
• a relative cuff pressure determining unit that determines the relative cuff pressure corresponding to the pulse wave detected by the pulse wave detector as a maximum of the single-parameter function or a maximum of a function generated based on the single-parameter function;
• and
• a blood pressure calculating unit that calculates the blood pressure of the subject by subtracting the determined relative cuff pressure from the cuff pressure detected by the pressure detector when the pulse wave detector detects the pulse wave,
• wherein the electronic blood pressure monitor uses the calculated blood pressure of the subject to evaluate the cuff pressure detected by the pressure detector when the pulse wave detector detects the pulse wave, changes the cuff pressure to an appropriate value and calculates the blood pressure of the subject at the changed cuff pressure.

An electronic blood pressure monitor comprising:

• a cuff configured to be mounted on a predetermined portion of a subject for pressurizing an artery of the subject;
• a cuff pressure controller for controlling a cuff pressure inside the cuff;
• a pressure detector for detecting the cuff pressure;
• a pulse wave detector for detecting a pulse wave of the artery that is pressured by the cuff;
• a wave feature calculating unit for calculating a wave feature value of the pulse wave detected by the pulse wave detector for each of a systolic blood pressure and a diastolic blood pressure;
• a function memory that stores, for each of the systolic blood pressure and the diastolic blood pressure, a two-parameter function having the wave feature value and a relative cuff pressure as parameters, the relative cuff pressure being a pressure difference between the detected cuff pressure and a blood pressure of the subject;
• a single-parameter function generating unit that generates a single-parameter function for each of the systolic blood pressure and the diastolic blood pressure by setting the wave feature value of the corresponding two-parameter function at the corresponding calculated wave feature value of the pulse wave detected by the pulse wave detector so that the single-parameter functions have the relative cuff pressure as a parameter;
• a relative cuff pressure determining unit that determines, for each of the systolic blood pressure and the diastolic blood pressure, the relative cuff pressure corresponding to the pulse wave detected by the pulse wave detector as a maximum of the single-parameter function or a maximum of a function generated based on corresponding the single-parameter function;
• a blood pressure calculating unit that calculates, for each of the systolic blood pressure and the diastolic blood pressure, the blood pressure of the subject by subtracting the determined relative cuff pressure from the corresponding cuff pressure detected by the pressure detector when the pulse wave detector detects the pulse wave, the blood pressure calculating unit calculating a systolic and diastolic average by averaging the calculated blood pressure corresponding to the systolic blood pressure and the calculated blood pressure corresponding to the diastolic blood pressure, and
• a blood pressure averaging unit,
• wherein the electronic blood pressure monitor repeats the calculation of the blood pressure of the subject at a plurality of the cuff pressures for each of the systolic blood pressure and the diastolic blood pressure, the blood pressure averaging unit calculates an average of the blood pressures of the subject calculated at the plurality of the cuff pressures for each of the systolic blood pressure and the diastolic blood pressure such that a higher weight is given to the calculated blood pressure having the corresponding systolic and diastolic average closer to the cuff pressure of the corresponding pulse wave detection.

An electronic blood pressure monitor comprising:

• a cuff configured to be mounted on a predetermined portion of a subject for pressurizing an artery of the subject;
• a cuff pressure controller for controlling a cuff pressure inside the cuff;
• a pressure detector for detecting the cuff pressure;
• a pulse wave detector for detecting a pulse wave of the artery that is pressured by the cuff;
• a wave feature calculating unit for calculating a wave feature value of the pulse wave detected by the pulse wave detector;
• a function memory that stores a two-parameter function having the wave feature value and a relative cuff pressure as parameters, the relative cuff pressure being a pressure difference between the detected cuff pressure and a blood pressure of the subject;
• a single-parameter function generating unit that generates a single-parameter function by setting the wave feature value of the two-parameter function at the calculated wave feature value of the pulse wave detected by the pulse wave detector so that the single-parameter function has the relative cuff pressure as a parameter;
• a relative cuff pressure determining unit that determines the relative cuff pressure corresponding to the pulse wave detected by the pulse wave detector as a maximum of the single-parameter function or a maximum of a function generated based on the single-parameter function;
• a blood pressure calculating unit that calculates the blood pressure of the subject by subtracting the determined relative cuff pressure from the cuff pressure detected by the pressure detector when the pulse wave detector detects the pulse wave;
• and
• a blood pressure averaging unit,
• wherein the electronic blood pressure monitor repeats the calculation of the blood pressure of the subject at a plurality of the cuff pressures, the blood pressure averaging unit calculates an average of the blood pressures of the subject calculated at the plurality of the cuff pressures such that a higher weight is given to the blood pressure calculated from the pulse wave having a greater amplitude.

An electronic blood pressure monitor comprising:

• a cuff configured to be mounted on a predetermined portion of a subject for pressurizing an artery of the subject;
• a cuff pressure controller for controlling a cuff pressure inside the cuff;
• a pressure detector for detecting the cuff pressure;
• a pulse wave detector for detecting a pulse wave of the artery that is pressured by the cuff;
• a wave feature calculating unit for calculating a wave feature value of the pulse wave detected by the pulse wave detector;
• a function memory that stores a two-parameter function having the wave feature value and a relative cuff pressure as parameters, the relative cuff pressure being a pressure difference between the detected cuff pressure and a blood pressure of the subject;
• a single-parameter function generating unit that generates a single-parameter function by setting the wave feature value of the two-parameter function at the calculated wave feature value of the pulse wave detected by the pulse wave detector so that the single-parameter function has the relative cuff pressure as a parameter;
• a relative cuff pressure determining unit that determines the relative cuff pressure corresponding to the pulse wave detected by the pulse wave detector as a maximum of the single-parameter function or a maximum of a function generated based on the single-parameter function;
• and
• a blood pressure calculating unit that calculates the blood pressure of the subject by subtracting the determined relative cuff pressure from the cuff pressure detected by the pressure detector when the pulse wave detector detects the pulse wave,
• wherein the cuff pressure controller and the pressure detector operate to increase the cuff pressure to a predetermined pressure with a predetermined tolerance.