Patent ID: 7575562

Claim:
A blood purification device comprising: a blood circuit having an arterial blood circuit and a venous blood circuit to circulate extracorporeally blood collected from the patient; a blood pump provided for said arterial blood circuit; a blood purification means, connected between said arterial blood circuit and said venous blood circuit, for purifying the blood flowing in said blood circuit; a venous blood pressure measuring means for measuring the pressure of a patient's blood flowing in said venous blood circuit; a venous blood pressure monitoring means for activating an alarm by comparing a predetermined alarm-threshold pressure with pressure measured or pressure predicted to be measured, as a base value, by the venous blood pressure measuring means; and a device that is configured to determine a time interval to update the alarm-threshold pressure of said venous blood pressure monitoring means by calculating a level of variation in the pressure measured by said venous blood pressure measuring means, wherein said venous blood pressure monitoring means updates said predetermined alarm-threshold pressure after said time interval.