Method and apparatus for monitoring blood pressure

Claim 1

A method of monitoring blood pressure of a subject, the method comprising the steps of: (a) continuously detecting pulse wave which is produced from an arterial vessel of a subject synchronously with heartbeat of said subject, said pulse wave consisting of a plurality of pulses, (b) measuring at least one blood pressure of said subject by inflating an inflatable cuff set on a body portion of said subject so as to press said body portion, and subsequently deflating said inflatable cuff, (c) selecting one of a first pulse group consisting of at least one pulse of the pulse wave detected during a first time period immediately before beginning of the inflation of said inflatable cuff, and a second pulse group consisting of at least one pulse of the pulse wave detected during a second time period following said first time period, such that said first pulse group is selected if a magnitude of the at least one pulse of said second pulse group is smaller more than a predetermined value than a magnitude of the at least one pulse of said first pulse group, and such that said second pulse group is selected if said magnitude of said at least one pulse of said second pulse group is not smaller more than said predetermined value than said magnitude of said at least one pulse of said first pulse group, (d) determining a relationship between blood pressure and magnitude of pulse wave, based on the measured at least one blood pressure and at least one magnitude of the at least one pulse of the selected one of said first and second pulse groups, (e) repeating the above steps (b) to (d) and thereby updating the relationship between blood pressure and magnitude of pulse wave, and (f) continuously determining blood pressures of said subject based on magnitudes of the pulses of the continuously detected pulse wave, according to a currently effective one of the repetitively updated relationships.

Claim 2

A method of monitoring blood pressure of a subject, the method comprising the steps of: (a) continuously detecting pulse wave which is produced from an arterial vessel of a subject synchronously with heartbeat of said subject, said pulse wave consisting of a plurality of pulses, (b) measuring at least one blood pressure of said subject by inflating an inflatable cuff set on a body portion of said subject so as to press said body portion, and subsequently deflating said inflatable cuff, (c) selecting one of a first pulse group consisting of at least one pulse of the pulse wave detected during a first time period immediately before beginning of the inflation of said inflatable cuff, and a second pulse group consisting of at least one pulse of the pulse wave detected during a second time period following said first time period, such that said first pulse group is selected if a magnitude of the at least one pulse of said second pulse group is smaller more than a predetermined value than a magnitude of the at least one pulse of said first pulse group, and such that said second pulse group is selected if said magnitude of said at least one pulse of said second pulse group is not smaller more than said predetermined value than said magnitude of said at least one pulse of said first pulse group, (d) determining a relationship between blood pressure and magnitude of pulse wave, based on the measured at least one blood pressure and at least one magnitude of the at least one pulse of the selected one of said first and second pulse groups, (e) repeating the above steps (b) to (d) and thereby updating the relationship between blood pressure and magnitude of pulse wave, and (f) continuously determining blood pressures of said subject based on magnitudes of the pulses of the continuously detected pulse wave, according to a currently effective one of the repetitively updated relationships.

Claim 10

An apparatus for monitoring blood pressure of a subject, the apparatus comprising: pulse wave detecting means for continuously detecting pulse wave which is produced from an arterial vessel of a subject synchronous with heartbeat of said subject, said pulse wave consisting of a plurality of pulses; blood pressure measuring means including an inflatable cuff which is set on a body portion of said subject, said means measuring at least one blood pressure of said subject by inflating said inflatable cuff so as to press said body portion, and subsequently deflating said inflatable cuff; selecting means for selecting one of a first pulse group consisting of at least one pulse of the pulse wave detected during a first time period immediately before beginning of the inflation of said inflatable cuff, and a second pulse group consisting of at least one pulse of the pulse wave detected during a second time period following said first time period, such that said selecting means selects said first pulse group if a magnitude of said at least one pulse of said second pulse group is smaller more than a predetermined value than a magnitude of said at least one pulse of said first pulse group, and that said selecting means selects said second pulse group if said magnitude of said at least one pulse of said second pulse group is not smaller more than said predetermined value than said magnitude of said at least one pulse of said first pulse group; first determining means for determining a relationship between blood pressure and magnitude of pulse wave, based on the measured at least one blood pressure and at least one magnitude of the at least one pulse of the selected one of said first and second pulse groups, said blood pressure measuring means, said selecting means and said first determining means being operated for repetitively updating the relationship between blood pressure and magnitude of pulse wave; and second determining means for continuously determining blood pressures of said subject based on magnitudes of the pulses of the continuously detected pulse wave, according to a currently effective one of the repetitively updated relationships.

Claim 11

An apparatus for monitoring blood pressure of a subject, the apparatus comprising: pulse wave detecting means for continuously detecting pulse wave which is produced from an arterial vessel of a subject synchronous with heartbeat of said subject, said pulse wave consisting of a plurality of pulses; blood pressure measuring means including an inflatable cuff which is set on a body portion of said subject, said means measuring at least one blood pressure of said subject by inflating said inflatable cuff so as to press said body portion, and subsequently deflating said inflatable cuff; selecting means for selecting one of a first pulse group consisting of at least one pulse of the pulse wave detected during a first time period immediately before beginning of the inflation of said inflatable cuff, and a second pulse group consisting of at least one pulse of the pulse wave detected during a second time period following said first time period, such that said selecting means selects said first pulse group if a magnitude of said at least one pulse of said second pulse group is smaller more than a predetermined value than a magnitude of said at least one pulse of said first pulse group, and that said selecting means selects said second pulse group if said magnitude of said at least one pulse of said second pulse group is not smaller more than said predetermined value than said magnitude of said at least one pulse of said first pulse group; first determining means for determining a relationship between blood pressure and magnitude of pulse wave, based on the measured at least one blood pressure and at least one magnitude of the at least one pulse of the selected one of said first and second pulse groups, said blood pressure measuring means, said selecting means and said first determining means being operated for repetitively updating the relationship between blood pressure and magnitude of pulse wave; and second determining means for continuously determining blood pressures of said subject based on magnitudes of the pulses of the continuously detected pulse wave, according to a currently effective one of the repetitively updated relationships.

Claim 17

A method of monitoring blood pressure of a subject, comprising the steps of: (a) detecting pulse wave which is produced from an arterial vessel of a subject in synchronization with heartbeat of the subject, the pulse wave consisting of a plurality of pulses, (b) varying pressure in an inflatable cuff set on a body portion of the subject, so as to inflate and deflate the cuff and thereby press said body portion, (c) measuring a maximum and a minimum blood pressure of the subject, by detecting an appearance and a disappearance of Korotkoff sounds as the pressure of said cuff is varied, (d) determining a maximum magnitude of a pulse of the pulse wave which pulse is detected when the pressure of said cuff is equal to the measured maximum blood pressure, and a minimum magnitude of a pulse of the pulse wave which pulse is detected when the pressure of said cuff is equal to the measured minimum blood pressure, (e) determining a relationship between blood pressure and magnitude of pulse wave, based on the measured maximum and minimum blood pressures and the determined maximum and minimum magnitudes, and (f) repeating the above steps (b) to (e) and thereby updating the relationship between blood pressure and magnitude of pulse wave, and (g) determining blood pressures of the subject based on magnitudes of the pulses of the pulse wave according to a currently effective one of the respectively updated relationships.

Claim 18

A method of monitoring blood pressure of a subject, comprising the steps of: (a) detecting pulse wave which is produced from an arterial vessel of a subject in synchronization with heartbeat of the subject, the pulse wave consisting of a plurality of pulses, (b) varying pressure in an inflatable cuff set on a body portion of the subject, so as to inflate and deflate the cuff and thereby press said body portion, (c) measuring a maximum and a minimum blood pressure of the subject, by detecting an appearance and a disappearance of Korotkoff sounds as the pressure of said cuff is varied, (d) determining a maximum magnitude of a pulse of the pulse wave which pulse is detected when the pressure of said cuff is equal to the measured maximum blood pressure, and a minimum magnitude of a pulse of the pulse wave which pulse is detected when the pressure of said cuff is equal to the measured minimum blood pressure, (e) determining a relationship between blood pressure and magnitude of pulse wave, based on the measured maximum and minimum blood pressures and the determined maximum and minimum magnitudes, and (f) repeating the above steps (b) to (e) and thereby updating the relationship between blood pressure and magnitude of pulse wave, and (g) determining blood pressures of the subject based on magnitudes of the pulses of the pulse wave according to a currently effective one of the respectively updated relationships.

Claim 23

An apparatus for monitoring blood pressure of a subject, comprising: pulse wave detecting means for detecting pulse wave which is produced from an arterial vessel of a subject in synchronization with heartbeat of the subject, the pulse wave consisting of a plurality of pulses; an inflatable cuff set on a body portion of the subject; cuff pressure varying means for varying pressure in said inflatable cuff so as to inflate and deflate the cuff and thereby press said body portion; blood pressure measuring means for measuring a maximum and a minimum blood pressure of the subject, by detecting an appearance and a disappearance of Korotkoff sounds as the pressure of said cuff is varied; pulse magnitude determining means for determining a maximum magnitude of a pulse of the pulse wave which pulse is detected when the pressure of said cuff is equal to the measured maximum blood pressure, and a minimum magnitude of a pulse of the pulse wave which pulse is detected when the pressure of said cuff is equal to the measured minimum blood pressure; first determining means for determining a relationship between blood pressure and magnitude of pulse wave, based on the measured maximum and minimum blood pressures and the determined maximum and minimum magnitudes, said cuff pressure varying means, said blood pressure determining means, said pulse magnitude determining means and said first determining means being operated for repetitively updating the relationship between blood pressure and magnitude of pulse wave; and second determining means for determining blood pressures of the subject based on magnitudes of the pulses of the pulse wave according to a currently effective one of the repetitively updated relationships.

Claim 24

An apparatus for monitoring blood pressure of a subject, comprising: pulse wave detecting means for detecting pulse wave which is produced from an arterial vessel of a subject in synchronization with heartbeat of the subject, the pulse wave consisting of a plurality of pulses; an inflatable cuff set on a body portion of the subject; cuff pressure varying means for varying pressure in said inflatable cuff so as to inflate and deflate the cuff and thereby press said body portion; blood pressure measuring means for measuring a maximum and a minimum blood pressure of the subject, by detecting an appearance and a disappearance of Korotkoff sounds as the pressure of said cuff is varied; pulse magnitude determining means for determining a maximum magnitude of a pulse of the pulse wave which pulse is detected when the pressure of said cuff is equal to the measured maximum blood pressure, and a minimum magnitude of a pulse of the pulse wave which pulse is detected when the pressure of said cuff is equal to the measured minimum blood pressure; first determining means for determining a relationship between blood pressure and magnitude of pulse wave, based on the measured maximum and minimum blood pressures and the determined maximum and minimum magnitudes, said cuff pressure varying means, said blood pressure determining means, said pulse magnitude determining means and said first determining means being operated for repetitively updating the relationship between blood pressure and magnitude of pulse wave; and second determining means for determining blood pressures of the subject based on magnitudes of the pulses of the pulse wave according to a currently effective one of the repetitively updated relationships.