Method and apparatus for blood pressure measurement

Claim 1

A method of measuring blood pressure of a subject through use of a cuff placed over a body part of the subject to apply a cuff pressure to a blood vessel in the body part, said method comprising the steps of: varying said cuff pressure as a function of time, and detecting said cuff pressure and a pulse wave produced in association with said blood vessel, to take repeated readings of said cuff pressure and said pulse wave; determining and recording a first and a second level of said cuff pressure as a systolic and a diastolic blood pressure, respectively, by analyzing said repeated readings of said cuff pressure and said pulse wave; providing a visible indication of values of said repeated readings of the pulse wave as a function of said cuff pressure, in the form of a two-dimensional graph representing said cuff pressure as a first variable along a first axis, and varying magnitudes of said pulse wave as a second variable along a second axis; attaching two marks to said graph at positions along said first axis, thereby indicating said first and second levels of the cuff pressure respectively determined as said systolic and diastolic blood pressures; and checking the recorded data of said first and second levels of the cuff pressure for validity thereof as to represent said systolic and diastolic blood pressures, by analyzing the positions of said two marks with respect to the indicated readings of the pulse wave magnitudes against a known characteristic of variations in the pulse wave magnitude in relation to the transition of the cuff pressure through the systolic and diastolic pressure levels.

Claim 2

A method of measuring blood pressure of a subject through use of a cuff placed over a body part of the subject to apply a cuff pressure to a blood vessel in the body part, said method comprising the steps of: varying said cuff pressure as a function of time, and detecting said cuff pressure and a pulse wave produced in association with said blood vessel, to take repeated readings of said cuff pressure and said pulse wave; determining and recording a first and a second level of said cuff pressure as a systolic and a diastolic blood pressure, respectively, by analyzing said repeated readings of said cuff pressure and said pulse wave; providing a visible indication of values of said repeated readings of the pulse wave as a function of said cuff pressure, in the form of a two-dimensional graph representing said cuff pressure as a first variable along a first axis, and varying magnitudes of said pulse wave as a second variable along a second axis; attaching two marks to said graph at positions along said first axis, thereby indicating said first and second levels of the cuff pressure respectively determined as said systolic and diastolic blood pressures; and checking the recorded data of said first and second levels of the cuff pressure for validity thereof as to represent said systolic and diastolic blood pressures, by analyzing the positions of said two marks with respect to the indicated readings of the pulse wave magnitudes against a known characteristic of variations in the pulse wave magnitude in relation to the transition of the cuff pressure through the systolic and diastolic pressure levels.

Claim 7

An apparatus for measuring blood pressure of a subject, comprising: means including a cuff placed over a body member of said subject for applying a cuff pressure to a blood vessel in the body member; means for gradually varying said cuff pressure; detector means for detecting said cuff pressure and generating pressure signals each representing a varying level of the detected cuff pressure, and for detecting a pulse wave associated with said blood vessel and generating pulse wave signals each representing a varying magnitude of the detected pulse wave; peak hold means for maintaining peak values of the wave form represented by said pulse wave signals; a memory for storing, synchronously with generation of said pulse wave signals, said peak values as the magnitudes of said pulse wave, and the corresponding levels of said cuff pressure represented by said pressure signals; output means for providing a visible indication of said peak values as a function of said cuff pressure, in the form of a two-dimensional graph representing said cuff pressure along a first axis and said peak values along a second axis; data processing means for controlling said output means to provide said visible indication, and determining and measuring a first and a second level of said cuff pressure as a systolic and a diastolic blood pressure, respectively, based on said peak values and said cuff pressure levels stored in said memory, said data processing means further controlling said output means to attach two marks to said graph at positions along said first axis to indicate said first and second levels of the cuff pressure which have been respectively determined as said systolic and diastolic blood pressures, whereby said graph and said two marks provide visible information for checking said first and second levels for validity thereof as measurement data to represent said systolic and diastolic blood pressures, said checking being made with reference to a known characteristic of variation in the pulse wave magnitude in relation to the transition of the cuff pressure through the systolic and diastolic pressure levels.

Claim 8

An apparatus for measuring blood pressure of a subject, comprising: means including a cuff placed over a body member of said subject for applying a cuff pressure to a blood vessel in the body member; means for gradually varying said cuff pressure; detector means for detecting said cuff pressure and generating pressure signals each representing a varying level of the detected cuff pressure, and for detecting a pulse wave associated with said blood vessel and generating pulse wave signals each representing a varying magnitude of the detected pulse wave; peak hold means for maintaining peak values of the wave form represented by said pulse wave signals; a memory for storing, synchronously with generation of said pulse wave signals, said peak values as the magnitudes of said pulse wave, and the corresponding levels of said cuff pressure represented by said pressure signals; output means for providing a visible indication of said peak values as a function of said cuff pressure, in the form of a two-dimensional graph representing said cuff pressure along a first axis and said peak values along a second axis; data processing means for controlling said output means to provide said visible indication, and determining and measuring a first and a second level of said cuff pressure as a systolic and a diastolic blood pressure, respectively, based on said peak values and said cuff pressure levels stored in said memory, said data processing means further controlling said output means to attach two marks to said graph at positions along said first axis to indicate said first and second levels of the cuff pressure which have been respectively determined as said systolic and diastolic blood pressures, whereby said graph and said two marks provide visible information for checking said first and second levels for validity thereof as measurement data to represent said systolic and diastolic blood pressures, said checking being made with reference to a known characteristic of variation in the pulse wave magnitude in relation to the transition of the cuff pressure through the systolic and diastolic pressure levels.