Patent ID: 7758532
Filing Date: 2010-07-20
Classification: A61M

Abstract:
1. A blood purification device comprising: a blood circuit having an arterial blood circuit and a venous blood circuit; a blood pump disposed in said arterial blood circuit, the blood pump being operable to provide a preset blood flow rate Qb; a blood purifier connected to the blood circuit between said arterial blood circuit and said venous blood circuit, and configured to purify blood flowing in said blood circuit, the blood purifier being operable to provide a preset water removal rate Quf; a first measuring unit disposed in said arterial blood circuit wherein said first measuring unit measures a first hematocrit value Hta of said arterial blood circuit; a second measuring unit disposed in said venous blood circuit wherein said second measuring unit measures a second hematocrit value Htv of said venous blood circuit; a calculating unit configured to calculate a measured ratio value and a theoretical ratio value, and then to calculate an evaluation value comparing a closeness of the measured ratio value to the theoretical ratio value, wherein: the first measured hematocrit value Hta is divided by the second measured hematocrit value Htv to obtain the measured ratio value Hta/Htv, and an evaluation unit coupled to the calculating unit and configured to evaluate whether the evaluation value is larger than a predetermined value; and said blood pump is further configured to adjust the preset blood flow rate to an adjusted blood flow rate when the trouble condition exists; said calculating unit is further configured to calculate a second measured ratio value and a second theoretical ratio value, said second measured ratio value referring to a ratio of said blood concentrations measured by said first measuring unit and said second measuring unit while said blood pump is operated at said adjusted blood flow rate and said blood purifier is operated at said preset water removal rate, and said second theoretical ratio value referring to a blood concentration ratio obtained by at least one formula based on parameters including said adjusted blood flow rate of said blood pump and said preset water removal rate of said blood purifier; said evaluation unit is further configured to evaluate whether a difference between said second measured ratio value and said second theoretical ratio value indicates the trouble condition; and said reporting unit is further configured to report the trouble condition for said blood purifier when said difference between said second measured ratio value and said second theoretical ratio value is at a first value which differs from a second predetermined acceptable ratio difference, and to report the trouble condition for said blood pump when said difference between said second measured ratio value and second theoretical ratio value is at a second value which differs from the second predetermined acceptable ratio difference.