Patent ID: 8328749

Claim:
A blood purification apparatus comprising: a blood circuit having an arterial blood circuit and a venous blood circuit to extracorporeally circulate blood retrieved from an access vessel of a patient; a blood pump provided in the arterial blood circuit; a blood purifying device connected between the arterial blood circuit and the venous blood circuit and configured to purify blood flowing through the blood circuit; an ultrafiltration device configured to apply a predetermined characteristic peak indicator to the blood flowing extracorporeally through the blood circuit, wherein the predetermined characteristic peak indicator is formed only by stopping the ultrafiltration device previously set at a fixed rate, and starting and operating the ultrafiltration device at a higher rate than the fixed rate for a period of time; a detecting device configured to detect the indicator applied by the ultrafiltration device; an arithmetic device capable of calculating, based on the indicator detected by the detecting device, a recirculation rate; and a calculating device configured to calculate an ideal extracorporeally circulating blood flow based on the recirculation rate, and communicate with the blood pump so that the recirculation rate is no more than a predetermined value when the recirculation rate calculated by the arithmetic device is greater than the predetermined value, wherein the recirculation rate is a proportion of a recirculated blood flow, which is reintroduced to the patient from the venous blood circuit and directed again to the arterial blood circuit, relative to an extracorporeally circulating blood flow.