Device for measuring blood flow velocity and quantity in aorta

Claim 1

An apparatus for measuring a blood flow velocity in an aorta, comprising: a cuff (200) including three bags of a blood flow shutting bag (220) for shutting a blood flow of an upper arm, a forward detection bag (210) for detecting a pulse wave heading to the blood flow shutting bag, and a rear detection bag (230) for detecting a pulse wave which has cleared the blood flow shutting bag; pressure control means (130, 140, 150) for retaining a reference internal pressure of the blood flow shutting bag and the respective detection bags at a systolic pressure SP; a forward sensor (110) for detecting as a forward pulse wave (Wf) a pressure change generated in the forward detection bag; a rear sensor (120) for detecting as a rear pulse wave (Wb) a pressure change generated in the rear detection bag with a delay time SPdt from a detection time of the forward pulse wave; calculating means (130) for dividing a distance L between the forward detection bag and the rear detection bag by the delay time SPdt to obtain a quotient, and outputting the quotient as a blood flow velocity VH of an aorta in a high pressure period.

Claim 3

An apparatus for measuring a blood flow velocity in an aorta, comprising: a cuff (200) including three bags of a blood flow shutting bag (220) for shutting a blood flow of an upper arm, a forward detection bag (210) for detecting a pulse wave heading to the blood flow shutting bag, and a rear detection bag (230) for detecting a pulse wave which has cleared the blood flow shutting bag; a forward sensor (110) for detecting as a forward pulse wave (Wf) a pressure change generated in the forward detection bag; a rear sensor (120) for detecting as a rear pulse wave (Wb) a pressure change generated in the rear detection bag with a delay time dt from a detection time of the forward pulse wave; pressure control means (130, 140, 150) for gradually decreasing a reference internal pressure of the blood flow shutting bag and the respective detection bags from a sufficiently high pressure for shutting a blood flow, and retaining the reference internal pressure as a pressure SP when the rear sensor detects a rear pulse wave for a first time; and means (130) for, while the pressure control means is retaining the reference internal pressure at the pressure SP, obtaining a delay time SPdt of the rear pulse wave with respect to the forward pulse wave, calculating a quotient by dividing a distance L between the forward detection bag and the rear detection bag by the delay time SPdt, and outputting the quotient as a blood flow velocity VH of the aorta in a high pressure period.

Claim 4

An apparatus for measuring a blood flow velocity in an aorta, comprising: a cuff (200) including three bags of a blood flow shutting bag (220) for shutting a blood flow of an upper arm, a forward detection bag (210) for detecting a pulse wave heading to the blood flow shutting bag, and a rear detection bag (230) for detecting a pulse wave which has cleared the blood flow shutting bag; a forward sensor (110) for detecting as a forward pulse wave (Wf) a pressure change generated in the forward detection bag; a rear sensor (120) for detecting as a rear pulse wave (Wb) a pressure change generated in the rear detection bag with a delay time dt from a detection time of the forward pulse wave; agreement judging means (130) for delaying the forward pulse wave by the delay time dt to superpose the forward pulse wave on the rear pulse wave, and judging whether or not lower parts of both the pulse waves agree with each other with a set precision; pressure control means (130, 140, 150) for gradually decreasing a reference internal pressure of the blood flow shutting bag and the respective detection bags from a sufficiently high value for shutting a blood flow, retaining the reference internal pressure as a pressure SP during a first period when the rear sensor detects a rear pulse wave for a first time, gradually decreasing the reference internal pressure after the first period of time is over, and retaining the reference internal pressure as a pressure DP during a second period when the agreement judging means agrees; means (130) for obtaining a delay time SPdt of the rear pulse wave with the forward pulse wave in the first period, dividing a distance L between the forward detection bag and the rear detection bag by the delay time SPdt to calculate a quotient, and outputting the quotient as a blood flow velocity VH of the aorta in a high pressure period; and means (130) for recognizing a rear pulse wave detected by the rear sensor in the second period as an approximate aortic wave near a heart, obtaining a systolic pressure SP, a diastolic pressure DP and a dicroticnotch pressure DNP based on the approximate aortic wave, calculating a coefficient R based on Equation R=(SP-DP)/(DNP-DP) , calculating a quotient by dividing the blood flow velocity VH in the high pressure period by the coefficient R, and outputting the quotient as a blood flow velocity VL of the aorta in a low pressure period.

Claim 5

An apparatus for measuring a blood flow volume in an aorta, comprising: a cuff (200) including three bags of a blood flow shutting bag (220) for shutting a blood flow of an upper arm, a forward detection bag (210) for detecting a pulse wave heading to the blood flow shutting bag, and a rear detection bag (230) for detecting a pulse wave which has cleared the blood flow shutting bag; pressure control means (130, 140, 150) for retaining a reference internal pressure of the blood flow shutting bag and the respective detection bags at a systolic pressure SP and a diastolic pressure DP; a forward sensor (110) for detecting as a forward pulse wave (Wf) a pressure change generated in the forward detection bag; a rear sensor (120) for detecting as a rear pulse wave (Wb) a pressure change generated in the rear detection bag with a delay time dt from a detection time of the forward pulse wave; means (130) for obtaining a delay time SPdt of the rear pulse wave with the forward pulse wave when the reference internal pressure is retained at the systolic pressure SP, dividing a distance L between the forward detection bag and the rear detection bag by the delay time SPdt to calculate a quotient, and giving the quotient as a blood flow velocity VH of the arota in a high pressure period; and means (130) for recognizing a rear pulse wave detected when the reference internal pressure is retained at the diastolic pressure DP as an approximate aortic wave, obtaining a blood flow effective sectional area SH of the aorta in the high pressure period based on a waveform of the approximate aortic wave before a dicroticnotch, and multiplying the blood flow velocity VH in the high pressure period with the blood flow effective sectional area SH in the high pressure period to give a blood flow volume in the high pressure period.

Claim 7

An apparatus for measuring a blood flow volume in an aorta, comprising: a cuff (200) including three bags of a blood flow shutting bag (220) for shutting a blood flow of an upper arm, a forward detection bag (210) for detecting a pulse wave heading to the blood flow shutting bag, and a rear detection bag (230) for detecting a pulse wave which has cleared the blood flow shutting bag; a forward sensor (110) for detecting as a forward pulse wave (Wf) a pressure change generated in the forward detection bag; a rear sensor (120) for detecting as a rear pulse wave (Wb) a pressure change generated in the rear detection bag with a delay time dt from a detection time of the forward pulse wave; agreement judging means (130) for delaying the forward pulse wave by the delay time dt to superpose the forward pulse wave on the rear pulse wave, and judging whether or not lower parts of both the pulse waves agree with each other with a set precision; pressure control means (130, 140, 150) for gradually decreasing a reference internal pressure of the blood flow shutting bag and the respective detection bags from a sufficiently high value for shutting a blood flow, retaining the reference internal pressure as a pressure SP during a first period when the rear sensor detects a rear pulse wave for a first time, gradually decreasing the reference internal pressure after the first period of time is over, and retaining the reference internal pressure as a pressure DP during a second period when the agreement judging means agrees; means (130) for obtaining a delay time SPdt of the rear pulse wave with the forward pulse wave in the first period, dividing a distance L between the forward detection bag and the rear detection bag by the delay time SPdt to calculate a quotient, and outputting the quotient as a blood flow velocity VH of the aorta in a high pressure period; and means (130) for recognizing a rear pulse wave detected by the rear sensor in the second period as an approximate aortic wave near a heart, obtaining a systolic pressure SP, a diastolic pressure DP and a dicroticnotch pressure DNP based on the approximate aortic wave, calculating a coefficient R based on Equation R=(SP-DP)/(DNP-DP) , calculating a quotient by dividing the blood flow velocity VH in the high pressure period by the coefficient R, and outputting the quotient as a blood flow velocity VL of the aorta in a low pressure period; means (130) for obtaining a blood flow effective sectional area SH of the aorta in the high pressure period based on a waveform of the approximate aortic wave before a dicroticnotch, and multiplying the blood flow velocity VH in the high pressure period with the blood flow effective sectional area SH in the high pressure period to give a blood flow volume in the high pressure period; and means (130) for obtaining a blood flow effective sectional area SL of the aorta in the low pressure period based on the waveform of the approximate aortic wave after the dicroticnotch, and multiplying the blood flow velocity VL in the low pressure period with the blood flow effective sectional area SL in the low pressure period to give a blood flow volume in the low pressure period.